Let's talk about Alkalinity, Calcium and Magnesium in an SPS Tank

[JB NY]

Ok so let's start a new discussion. This time I think it would be a great idea to get some of the basics down. So the topic will be Alkalinity, Calcium and Magnesium. Please note if you are going to participate in this discussion. Please stay on topic. This is not the place to ask where to buy something or just to pop in a state what you use. If you are going to post here please try to add something constructive. I am all for people agreeing with a members comments and such, but if there are posts that seem to be taking away from the discussion, they will simply be removed from the thread. OK back to the topic.

I choose these three to discuss together, because getting the correct numbers on each is essential for maintaining all.

I am going to give a run down on how I choose to remember and use each of these elements for my tank. Others feel free to comment and add on to what I have written. I am not a chemist and never claim to know half of what is needed to be a chemist, so with that disclaimer out of the way, here we go.

Alkalinity.
Trying to actually read on what Alkalinity is will most likely give the average reader a headache to say the least. It seems that this one little parameter is cause for much confusion when it comes time for a definition. I guess the pure way of thinking about what it really is, is a measure of available bicarbonate in the water that can be used for corals to take in to use to secrete their calcium carbonate skeletons. But mostly I think it is best thought of as two things. A buffer for pH, meaning that the correct alk (and higher alk ) will help to keep your pH from fluctuating too much. Alk is also a needed component for keeping acroporids as these corals consume alk in order to survive and grow. The school of thought for a long time was that if alk shows how much bicarbonate is available to be taken up by corals and can also limit pH swings, then higher than normal levels would be best. Most people recommended that we keep out Alk levels at 10-12 dKH. Over time myself and many others, keeping primarily acroporids as well as other SPS, found that the high end of the dKH scale is not always better and that keeping alk closer to natural sea water levels of ~8dKH yielded good, if not better, results for SPS. My personal experience is that I found much less incidence of RTN and my pH became just as stable when balanced with the proper levels of calcium and magnesium. So my recommendation is to keep alk around 8-9 dKH for keeping acroporids. Another nice benefit of lower alk was less precipitate on heaters and pumps.

Calcium.
A little easier to define. Calcium is used by our corals to grow. Natural seawater levels are around 380-400ppm. The role that alk and calcium have is that the two of them compete for space in the aquarium. having too much of one will limit what one can have of the other. Generally you can have low alk and high calcium, or high alk and low calcium, and in between the two is that sweet spot that most people try to hit. If you are having trouble getting your alk and calcium values in line you should check out Randy's article on fixing alk/calcium problems it gives some really nice graphs that are helpful.

http://web.archive.org/web/20021127040526/http://www.advancedaquarist.com/issues/nov2002/chem.htm

Personally I think you should not go below 400ppm on calcium. And I have had the best success with high levels of calcium between 450 and 500 ppm. I feel that this allows me to get a very good growth in my aquarium. I had kept my calcium levels at around 360-380 for a few years and while this did not cause any problems, my growth wasn't anything to brag about. High ca levels really pushed my growth up a huge notch. Note, that I keep low levels of alk in my tank so that helps me to keep a higher level of ca in the aquarium as well.

Magnesium.
In all honesty I don't understand magnesium as well as the other two parameters. I know that corals do take in magnesium so it is needed on that level. But most importantly I know that having the proper amount of magnesium in your reef is essential to maintaining proper alkalinity and calcium levels. Inadequate levels of magnesium can lead to using a tremendous amount of supplements trying to maintain the proper levels of calcium and alkalinity. So if you ever find yourself struggling to maintain alk and ca check to see if your mag levels are adequate. IMO, a minimum level of 1300 ppm should be the goal when it comes to magnesium levels. This is important to know because many, many salt mixes are deficient in magnesium and many times one will have to add magnesium to freshly made salt water prior to doing a water change. Otherwise you magnesium levels will drop with each water change you do.

I personally like to maintain magnesium levels at 1450-1500 ppm. For me that has worked out best. it allows me to easily maintain my alk and ca levels and my corals seem to do best at this level as well.

OK that's it for a little while. Please feel free to comment on anything I have written, please add you own thoughts and experiences as well. I'll soon post in this thread my means of supplementing all of these in my tank as well and my thoughts on what works best for my setup and why I feel that way.

If you have any comments on this thread, or have an idea for another thread please post your thoughts here

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1176047

[JB NY]

Here is my thoughts on supplementing.

For alk only. I have always used Seachem Reef builder. It's not too expensive near me. I only add it when something is out of line with alk only.

For Calcium only. I use Kent's turbo calcium. Again only used when something is out of line with my calcium only

For determining how much of each supplement to use I have been using jdieck (http://www.reefcentral.com/forums/member.php?s=&action=getinfo&userid=18470)'s calculator

http://reef.diesyst.com/

For both my Calcium and alk needs I use both a calcium reactor and a neilson (Kalkwasser) reactor. You can use two part additives (hopefully people will chime in who use them) but for me I find that the calcium reactor is a set it and forget it setup. Once it is dialed in I only look at it once a week to make sure that everything is working correctly, the rest of the time, I don't even worry about my alk and calcium levels.

If you need an introduction to calcium reactors in general. Here is a short primer that I put together to help you understand the basics.

http://www.cnidarianreef.com/faq.cfm?FID=37

As to why I use a kalk reactor in addition to the calcium reactor? I like using kalkwasser as it helps me to maintain a higher pH due to the calcium reactors tendency of pulling down the tank pH. Also over the years I have felt that it does help with growth and coloration to a small extent. Meaning that I can generally tell by looking at my tank when my kalk reactor needs to be filled as the corals just look a little bit different. Perhaps some other people can comment on using a kalk and a calcium reactor together. If you have noticed similar things or is it all in my head. :)

As for magnesium. Once I get the main tank up and running with the correct magnesium levels. I only supplement magnesium in the water used for water changes. Other than that I never add it to the main tank. I do weekly water changes, so perhaps the frequent exchange of fresh water helps to keep the magnesium levels from dropping.

Also, I do check the alk/ca/mag levels of a new batch of salt before I do the first water change with it. From here I adjust the levels of the newly mixed salt to match that of my main tank for the remainder of the salt batch.

[JetCat USA]

Agreed for the most part, i have found the best results with Ca between 400 and 450, Alk at 9.6 dKH but Mg a little lower then yours, i keep mine around 1300, I've only noticed problems keeping Ca up when it gets down below 800ish and coral growth I've not noticed a significant difference with it from 900 to 1600.

[gary faulkner]

Joe,
How often do you test and what brand do you recommend for testing?

Just want to say, glad we are starting with the basics.

[naka]

I think key to success in SPS tank is keeping your parameters stable. I nearly went through entire Salifert ALK test kit while fine tuning my calcium reactor. Now I only test for ALK/Calcium once a week.

I've had problems when my ALK was above 9 for some reason. I've experienced tip recession and stn on few of my corals. Now I keep my ALK around 7 -8 dkh, but never above 8 dkh.

Calcium is one the easiest to maintain for me. It's never been an issue. I keep mine 420 - 440 ppm stable.

I get really lazy when it comes to MG levels. I check mine once a month. I have some MG granules in my calcium reactor, so I don't add any MG to my tank. It's always around 1500 ppm when I test my water.

Nice thread Joe.

[JB NY]

gary faulkner If one of my parameters is not right, I test, dose any additives and retest 24 hours later. Then once everything is correct. I only test once a month. 90% of the time my parameters are almost exactly the same month after month.

Naka I completely agree. I forgot to add that one should strive very hard to not have the parameters vary much, if at all. Stability is a great and powerful thing in a reef tank. Work hard to keep things stable and good things always follow.

For people who are testing junkies, if you are going to do testing more than once a week. I wouldn't do it less than 24 hours apart and I would say to try and test the same time each day.

[kev apsley]

let me just add that I use B-Ionic 2pt for my ca/alk needs. It should be noted that regular testing of both calcium and alkalinity should be done while trying to find that sweet spot.

Also, the bioload will change overtime, as corals grow and and their demand for calcium increases people using a 2pt system need to always be aware that their dosing amounts will also increase to keep up with the demand...test..test...test

[jeffbrig]

<a href=showthread.php?s=&postid=10500592#post10500592 target=_blank>Originally posted</a> by JB NY
Magnesium.
In all honesty I don't understand magnesium as well as the other two parameters. I know that corals do take in magnesium so it is needed on that level.

The primary benefit of Mg is that it allow calcium and bicarbonate levels in the water to exist at supersaturated levels. In laymen's terms, having high Mg allows you to maintain higher Ca/Alk.

Because Ca and bicarbonate are supersaturated, they are always ready to fall out of solution. This is the abiotic precipitation that every talks about on heaters, pumps, and solid surfaces. As calcium carbonate forms on these surfaces, Mg is also able to bond with it. By doing so, Mg blocks Ca and bicarbonate from being able to attach, significantly slowing the rate of precipitation. If you let Mg drop, you have to pour in more and more Ca and Alk supplements, and precipitation becomes more and more of a factor.

I don't think corals deliberately use (or require) Mg, it's more of an incidental pick-up while building their skeletons. But, maintaining Mg levels is necessary to hold Ca and Alk levels where you want them.

[cham]

Great article.

I use homemade two part made from Baking Soda & Ca chloride. I also use MAG flake & Epsom but like JB NY I rarely ever need MG supplimentation. Reef Crystals does a pretty good job.



I however prefer to dose my sps system with two part & kalk. I dose the two part using reef dosing pump.com unit and a 5 gallon jug for CA & another for ALK. I set my dosing rate, test like a mad man for a couple few weeks to see if its too much or too little and at that point it is "set it & forget it" for me too.

I also run a lower PH naturally (C02 levels in the home) that I have tired to remedy with an air pump bringing in outside air into skimmer intake with no great help. So to add a CA reactor to a system that already runs 7.9 to 8.0 daily swing didn't seem like a good alternative to me.

I also use kalk in my ATO at full saturation controlled by a PH controller & dual float switch so that my kalk is only dosed when PH falls below a certian level and turned off once PH gets back up or the sump reaches a pre set height.

Once my demands on my tank increases, its as easy as turning a knob on my doser to increase my rate from 10 ml's to 15 or 20 as shown on the LED display. It will dose all the way up to 500 which IIRC is up to 85 ml's per hour per channel. Would be awesome to have a system that needs that type of supplimentation. :)

[Scuba Dog]

I have a great deal of experience with chemical testing and the normal day to day operations of a multi million dollar chemical production unit. A sps tank and a chemical plant have a lot in common with all the equipment, maintance, reactions, and testing.

I learned that its better not to over test(repeated redundant sampling) that can leed to unnecessary adjustments, though a falty test result. In other words dont let a falty result cause you to get your tank out of balance.

When you make an adjustment it is better to make a small adjustment then sit back an wait a day or two for the system to stabilize(knee jerk reactions can be a killer).

My recomendations for maintaining alk, ca, Mg is to get a quality test kits, and keep them in a cool dry area, and keep in mind that over time the reagents in the kit can and will go bad. Also develop a good consistant technique for your titrations. Titrate slowly till you think you hit end point( color change) then add a couple more drops to make sure. If you get a bad result or one that just dosent make sence then retest and see if you can reproduce the number. Who know it could be an accurate result then its time to go trouble shooting and inspect your equipment.

In my opnion in brine chemistry its way better to go slowly on setting up calcium reactors and kalk stirers, even when dosing two or three part additives. At least until you have a real good feel on how your system is performing

[Cultivatedcoral]

I keep my alk at 6-8 dkh, Ca at 430-450 and MG 1300-1400 and postassium at 380-400. Sorry had to at that too. My name is zeorocka!! haha

[teen]

is it true that low levels of magnesium can lead to poor colors in sps corals? my alk and calcium are in line, but i dont test for magnesium, and im thinking its on the low side. recently ive been having some browning issues, and i dont know what to blame it on.

[gasman059]

I look at them as the holy trinity. All 3 go hand in hand and IMO should be measured consistently.

[Philwd]

I recently let my Mg levels get low. ~ 960. My testing had gotten sporadic as it always tested 1350. I had started getting tip recession and blamed it on alk. Now that the Mg is back in line everything thing is getting back to normal.

[TandN]

This is a great thread and yes Stability is KEY I just wish there was a more reliable ALK test kit

[Sk8r]

I am in a bit of a situation, or I landed in one, when I moved, had my rock crash and cook because of a delay in setup: I had to go ahead and put all my corals [held at my lfs] into a raw new tank, and I lost the mille. Bear with me: this does somewhat bear:

I have always dosed Kent Turbo Calcium, Kent Mg, and Kent Dkh Alkalinity Buffer, testing every 3 days, never able to get cal much above 400, mg about 1200, alk about 8.3 no matter what I did...in the old setup.

Knowing I was in trouble, I set up a 20g refugium, got a kalkreactor, and now maintain a much steadier 420 calcium, 9.3 alk, and about 1400 mg. The surviving sps are beginning to come back, not yet regrowing rtn'd areas, but thickening tissue in 'good' areas and turning quite strongly green/orange, etc, as appropriate---acropora aculeus [I think] and a definite several montiporas: as yet not a bit of polyp extension, but phosphate levels are dropping significantly [kalk is alleged to precip it out: don't know, but it is dropping, since algae is going away.]

I'm pretty steady at 420 c, 9.3 alk, and 1400 mg, and I'm liking that level, based on the reaction of some really badly abused sps. I'm determined to get this tank back on track post-move, and I'm happy to hear others opine that that's not a bad range to be in.

What else has changed for me is stability. I'm only a 54g, with a 30g sump/refugium, and I've gone from a daily dose and 20 point flux in most readings, to no flux to speak of. Being as small a tank as this is, the kalk is able to hold it steady, with only once a month dosing, and I think this is going to be a vast improvement over my old situation, [I had buffer supplied by the topoff, but had a fierce alk build-up, over time: I know everybody says if you get an alk spike it's harmless and just let it fall naturally---but I lost 4 acroporas in that period. So if I ever get another such alk spike [though the old method of dosing is now done-with] I will be much more aggressive about remediating it with water changes. My current goal is not to let such things happen.

[ReefWreak]

Sk8r sorry to hear about your problems with alk spikes, however it's not an uncommon problem, usually with disasterous results. A local wasn't paying enough attention when he set up his calcium reactor and as a result got an alk spike that killed a few of his corals in his tank. I've heard similar stories from people around RC as well, so it's not uncommon of a problem.

JBNY thanks again for another great discussion piece, as your tutorials have always been helpful to myself as well as many, many other beginners. It's amazing the things we learn in this hobby whether it be about biology, chemistry, or nature in general, our knowledge is strengthened by people like you who make an effort to round up the information to be easily passed through the ranks in an effort to increase success across this whole hobby.

Stability FTW. I'm still dialing in my CA reactor so I can run with the big dogs :)

[dukes707]

i agree with Gasman059 about the sps holy trinity being cal/alk/Mg. they all share a relationship, although nonlinear in some cases, all are relative to eachother in respect to keeping things stable. all should be tested and kept as stable as possible.
i use kalkwasser in an ATO for all top off water. pH stays rock solid @ 8.2. i recently got through a bout with wack alk due to a faulty salifert kit i had and my Mg was off by a large margin due to using only kalk as my cal/alk additive. i wasent aware of the amount of Mg depletion that occurs with using only kalk, and i paid for it. and got an API for alk.
thanks to randy's informative articles on mg and kalk i was able to remedy the situation before losing too many sps'. some are still recovering from the subsequent brown out. my alk fell to about <6 but after correcting my mag levels with randys two part #3 mag supplement mix and supplementing with some bakng soda after about a lil over a week things are finally getting back to relative normal.
word to the wise, whatever supplementation system you use make sure you understand it completely, pros and cons. read as much as you can on whatever system you are using.
now that things are stable again, and polishing waterchange water with Mg additive prior to changing things are rock solid.
cal~400 alk~8.5 mg~1350 pH-8.2 steady. i like to ry to keep things as close to NSW, and my critters seem to appreciate it more than keeping things supersaturated and at the high end of the params. my experience with my system and what supps i use.

[Aquarist007]

I really appreciate what I have read so far--thanks.

I am still trying to grasp my fluctuating pH over a week it will drop from 8.3 to 7.7. I am aware that carbon dioxide plays a big part in this. However I just read above that a stable alkalinity level will help maintain the the stability of the pH level. My alkalinity has been stable at 8.5----and in the past I have had it as high as 13.dKh(stable) but the same fluctuation in pH occurs?

Opening windows etc will raise the pH slightly but not really that much. I used to use the kent reef builder but I am aware that it raises the alkalinity also(this is how I ended up with 13 dKH)
I am also aware that I could use Kalkwasser to build up the pH and not the alkalinity.
I am confused at what route to take?

[Sk8r]

This is what I know about supplementation: if you hand-dose, you need to test at the same time every day to try to minimize the swing. I got into serious trouble letting an unstirred 7g ro/di bucket do my alk supplement. Bad idea. That let to, eventually, a buildup that finally got dosed when the bucket ran low: hence the spike.

A kalk reactor, supplying both alk and cal, can contribute to ph problems, but I can say my gallon + a day evaporation rate and small tank size [54g] makes an ideal situation for kalk as THE supplement---so far. Corals can get very hungry, and once the fast-growing montiporas really get started, it may be different, but right now the reactor will hold the 54g steady with only set-up dosing.

Some people run both a calcium reactor AND kalkreactor.

And stability I'm sure is a big item in the benefits. That and precipitation of phosphate via kalk [unproven, meaning I've never found any article with research] but...my tank algae is going away.

Does anybody know whether the ocean has 24 hour cycles in ph, alk, cal? Is there any net effect of dark period and coral absorption cycles re the condition of the water in the immediate surrounds of a reef?

[JB NY]

<a href=showthread.php?s=&postid=10503028#post10503028 target=_blank>Originally posted</a> by teen
is it true that low levels of magnesium can lead to poor colors in sps corals? my alk and calcium are in line, but i dont test for magnesium, and im thinking its on the low side. recently ive been having some browning issues, and i dont know what to blame it on.

I've never seen low mag cause browning issues. My mg was at 900 for a long time before I caught it. None of my corals were brown at the time.

capn_hylinur Sometimes if you are pushing your ca reactor too hard it can cause lower tank pH. The only suggestion is to try and dose some kalk at night. I used to mix a teaspoon of kalk with a little ro/di water and just tossed it in the sump. I did that a few years back when I was having large pH fluctuations. The ultimate solution was to get a different ca reactor that didn't have to work so hard, but that's another story.

[JB NY]

Yeah getting the right amount of dosing can be challenging and as many people wrote, the more your corals grow the more demands are placed on the tank so you need to adjust things. Sometimes when adjusting you find the parameters bouncing up and down till you get things stable. It can be frustrating trying to get things dialed in but once your do. The tank does well. Getting everything stable is key though. Everyone has brought up that point but it is very true.

Keeping the parameters is nice, keeping it all very stable is great!

[Randy1]

One thing you don't want to do is wait till your levels are off to add anything Cal. or Alk. or mag. You need to detemin your demand. I have settled in with 1 cup of 2 part calc. and alk. daily and 1 cup of mag 2 part twice a month. If I add some corals then I'll begin monitoring these levels and adjusting upward as needed. You should add calc. and alk. daily to keep it stable.

[Sk8r]

I'd add: a log book is your friend. If you keep a log of what you added and what the reading was on the following day, you can spot trends and correct before you're into bad territory.
You also learn how your particular tank reacts, and you can smooth out the peaks and valleys of calcium/buffer.

[solbby]

<a href=showthread.php?s=&postid=10501353#post10501353 target=_blank>Originally posted</a> by jeffbrig

I don't think corals deliberately use (or require) Mg, it's more of an incidental pick-up while building their skeletons. But, maintaining Mg levels is necessary to hold Ca and Alk levels where you want them. All protein synthesis, DNA replication and most enzymatic process use Mg as a co-factor. It is incredibly important for biosynthesis.

Not trying to be nit-picky just bringing a thought to the table, :) .

[bradleyj]

Joe, I dose with Seachem Reef builder also when my alk gets low. Can you add this when you make your saltwater for a waterchange ? like you do with mag? Or is it better to just mix with ro/di?

[JB NY]

<a href=showthread.php?s=&postid=10512213#post10512213 target=_blank>Originally posted</a> by bradleyj
Joe, I dose with Seachem Reef builder also when my alk gets low. Can you add this when you make your saltwater for a waterchange ? like you do with mag? Or is it better to just mix with ro/di?

Yeah you can.

This is what I do when I do a waterchange. Fill up the bucket with ro/di water then add the salt. Then add whatever additives I need to get that water the same levels as is in my tank. for the alk and calcium additives I still mix them in a cup of ro/di water before adding it to the new saltwater.

[SDguy]

But only if you are trying to raise the alk of the new water to bring it to an acceptable level. Trying to add extra, so as to raise your tank alk this way could very likely cause a precipitation effect in the new water. I'm sure this is not not Bradleyj meant, but I wanted to just clarify in case anyone reading this thought this way. :)

BTW Joe, I'm with you on the Magnesium. I found (in this tank and my previous tank) with Mg at 1100ppm or so, I could NEVER get my Ca above 360ppm.

[JB NY]

<a href=showthread.php?s=&postid=10514102#post10514102 target=_blank>Originally posted</a> by SDguy
But only if you are trying to raise the alk of the new water to bring it to an acceptable level. Trying to add extra, so as to raise your tank alk this way could very likely cause a precipitation effect in the new water.

Good point.

<a href=showthread.php?s=&postid=10514102#post10514102 target=_blank>Originally posted</a> by SDguy
BTW Joe, I'm with you on the Magnesium. I found (in this tank and my previous tank) with Mg at 1100ppm or so, I could NEVER get my Ca above 360ppm.

Yeah so many calcium problems could be fixed faster if people would test their Mg more often. I test mine about as much as I do my calcium.

[Aquarist007]

<a href=showthread.php?s=&postid=10508521#post10508521 target=_blank>Originally posted</a> by JB NY

capn_hylinur Sometimes if you are pushing your ca reactor too hard it can cause lower tank pH. The only suggestion is to try and dose some kalk at night. I used to mix a teaspoon of kalk with a little ro/di water and just tossed it in the sump. I did that a few years back when I was having large pH fluctuations. The ultimate solution was to get a different ca reactor that didn't have to work so hard, but that's another story. [/B]

thanks JB NY but I am not running a calcium reactor. For the last year I have been using Randy's article on Solving alk and pH problems. I am due for a water change---maybe I should start over using the b-ionic two part system and try to bring stability back to the pH.?
Is a big flucuation in pH a problem for SPS corals or should it just be ignored and worry about alk calcium and magnesium(those are very stable right now)

[Sk8r]

To my knowledge, corals don't like rapid change in any parameter. I'd try to eliminate any bounce in anything to do with water, though I can't point to any specifics regarding ph. I'd *think* that it might affect the condition/penetrability of their 'skin,' making it more or less vulnerable to bacteria, etc, but that's only guesswork. The more 24/7 any 'good' situation is, the more corals are going to settle down and do their thing: I think that's safe to say.

[piercho]

Does anyone have concerns over the rise in sulfate when adding epsom salt (MgSO4) to bring up Mg? I think some of the hobby Mg additives may also be mainly MgSO4. For people doing a 1100 to 1400 Mg bump with epsom salts, you could be getting a dramatic rise (44%) in SO4 levels. Magnesium Supplements, RH Farley (http://reefkeeping.com/issues/2006-07/rhf/index.php)

[JB NY]

I would say if you only use epsom salt that sulfate would be a concern. I've never used it for that reason. I've used ESV liquid mag in the past. But will be trying out Magnesium Chloride in the future.

[JetCat USA]

<a href=showthread.php?s=&postid=10516276#post10516276 target=_blank>Originally posted</a> by JB NY
I would say if you only use epsom salt that sulfate would be a concern. I've never used it for that reason. I've used ESV liquid mag in the past. But will be trying out Magnesium Chloride in the future.

Regular water changes help control the ionic imbalances caused by just using the Epsom salt. you run into the same issues with the use of just MgCl with it being the chloride ions that get imbalanced. the best is to mix 3 parts MgSO4 to 5 parts MgCl.

[SaraB]

Great Thread! It reminded me to quit wasting my time trying to dose Alk and Calcium and concentrate on the Magnesium first. I order Kent Tech M by the gallon jugs! Does anyone else have good luck with Tech M or is there something else better out there?

[JetCat USA]

buying your own MgCl and MgSO4 is much cheaper long term if you have allot of water volume.

[SaraB]

<a href=showthread.php?s=&postid=10516457#post10516457 target=_blank>Originally posted</a> by JetCat USA
buying your own MgCl and MgSO4 is much cheaper long term if you have allot of water volume.

Thanks. I will have to re-read Randy's recipe and try to locate the ingredients locally as I know it will save me some money. I still have 2 gallons of Kent left, but with 500 gallons of water, it will go quick enough.

[IPT]

I am really new to all of this and learing day by day. This site is awesome! I understand Joe that you and many other keep the Alk a little lower and Ca a little higher - relatively speaking. Does anyone do the opposite? I seem to recall reading something about "farming" that recommended higher Alk (~12, and lower Ca ~320) for faster growth. It was possible that color may be sacraficed though. Anyone experience that? Does it make sense to do that a while for someone with lots of frags and then slowly transition to the inverse as the tank matures and colonies grow? I don't know, just a thought since this is a disussion I thought I'd throw it out there. I don't have enough experience to comment but hopefully some of you do.

[piercho]

JetCat, I had to hunt for the basis of your 3:5 MgSO4:MgCl ratio recommendation. Improved 2-Part Supplement Article; Farley (http://reefkeeping.com/issues/2006-02/rhf/index.php#7): Recipe #1, Part 3A. But to get the desired final ion ratio (table 2), I think that you also have to be using the 2-part additives alone to keep Ca and carbonate up? If you are using limewater and a calcium reactor instead of the 2-part additives for Ca and carbonate, wouldn't you want to use a 1:10 MgSO4:MgCl ratio as Farley recommended in the origonal Mg supplementation article? I'm not clear on that point.

I'm off to YellowKnife Canada for 10 days and hope to catch a fish or two. I hope you guys keep this up.

[JB NY]

<a href=showthread.php?s=&postid=10516325#post10516325 target=_blank>Originally posted</a> by JetCat USA
you run into the same issues with the use of just MgCl with it being the chloride ions that get imbalanced.

:( What does a choride imbalance do? I thought the ESV liquid Mg was magnesium choride.

<a href=showthread.php?s=&postid=10516752#post10516752 target=_blank>Originally posted</a> by IPT
I seem to recall reading something about "farming" that recommended higher Alk (~12, and lower Ca ~320) for faster growth.

I don't think that would work. Higher Ca almost always equals higher growth. Acros in my tank grew like grazy with high Ca. with my Ca at 500 and Alk at 8 dKH I was able to pull a good 30 frags (min size 1 1/2") a month out of my 180.

[naka]

Another tip in raising ALK is to raise it SLOWLY. I see too many people trying to raise ALK overnight using Part B, baking soda, etc... Instead of using baking soda to raise it, I like to drip Kalk overnight. Then test your water after 24 hrs, not very next morning.

[JetCat USA]

piercho

in order for a CaCO3/CO2 reactor to dissolve Mg the pH would have to be considerably lower then we run (to the point it would mud the media pretty quickly) therefore any Mg that's in your media is coming out as a precipitant and does little for helping keep the tanks levels up. back yrs ago we all used to add a few handfuls of Dolomite to the reactor but it never did any good.

the 3-5 ratio is balanced, i don't see why it would then be unbalanced just because you use a CaCO3/CO2 reactor or Kalk, if that were true, then using the reactor or Kalk without a Mg supplement would also be throwing your system out of ionic balance, i think most would agree that's not happening.

Joe

it's my understanding that one ionic imbalance is just as bad as the other. with that said if you have to use just a single additive the imbalance is lesser by the use of MgCl then the use of MgSO4 for the same ppm increase for a given volume of water.

[IPT]

Science is often behind the real world and lab testing results are not always easily transferable to reality. That being said, in Randy's artical (http://www.reefkeeping.com/issues/2004-05/rhf/index.php), unless I am misunderstanding, it seemed that raising alkalinity above nautral seawater levels had more effect on growth rates than raising Ca. That was a sterile environment - and there was no mention of coloration or any other measure besides calcification. I have held my Alk higher and Ca a little lower and this thread is making me reconsider that philosophy.

[piercho]

Sarah,
2-Part Solution, an RC sponsor, sells the dry chemicals to make Randy's Ca/Carbonate/Mg additives. They have the chemicals either in bulk or in pre-portioned packages to make standard solutions of known concentration. There is also a calculator on their website that will assist to figure out the dosing volumes of the standard solutions. If I knew another site offering the dry chemicals in conveniant volumes I would point it out, but the only one I'm aware of is 2-Part and I have used them.

JetCat, I'm saying that I think that the 3:5 ratio winds up being balanced (with respect to Cl and SO4) only if you have Na and Cl being added from the other parts of the two-part solution. To get the final ion ratios in table 2, I think you have to use all three parts. If you are using limewater and/or a calcium reactor instead for Ca and carbonate you aren't adding the Na and Cl that would be added if you were using 2-part. So when you use part 3A for Mg, your chloride and sulfate ratios increase with respect to the other major ions. And the sulfate ratio could climb quite steeply. For people not using the Ca or carbonate 2-part components, I would think that you would want to use mostly MgCl to boost Mg, as Randy said in the origonal Mg supplement article.

That is how I figure it, but I'm no chemist that is sure. And it seems if you exchange enough water frequently enough, the major ions should stay pretty much in line anyway. At least thats what I took away from the Randy's Mg supplementation article.

[stony_corals]

Solbby, is the Mg that is used taken from the water column or from food?

If you are using MgCl and MgSO4 to raise Mg levels, you shouldn't use the formula that Randy uses in conjunction with his two part. You should use 7 1/4 cups of MgCl to , I believe, 1 3/4 cups MgSO4 to a gallon of water. The Mg formulation when used with the 2 part is balanced when used with the two part, otherwise, it's unbalanced.

I'm slowly trying to raise one sys to the "Italian" levels 1500 Mg, 500 Ca, 10-11 dKH, do we'll see how that goes with sps....

[Aquarist007]

<a href=showthread.php?s=&postid=10516437#post10516437 target=_blank>Originally posted</a> by Sara B
Great Thread! It reminded me to quit wasting my time trying to dose Alk and Calcium and concentrate on the Magnesium first. I order Kent Tech M by the gallon jugs! Does anyone else have good luck with Tech M or is there something else better out there?

Sarah, probably you measured your mag first---what is the reading. I dosed with Seachem mag for about a month every other day--the reading has been 1350 and stayed there--I haven't dosed mag for at least 3 weeks either and it is staying there. I think once you get the mag up to 1300 it stays there without alot of dosing.

[SaraB]

<a href=showthread.php?s=&postid=10517744#post10517744 target=_blank>Originally posted</a> by capn_hylinur
Sarah, probably you measured your mag first---what is the reading. I dosed with Seachem mag for about a month every other day--the reading has been 1350 and stayed there--I haven't dosed mag for at least 3 weeks either and it is staying there. I think once you get the mag up to 1300 it stays there without alot of dosing.

Dosing daily I have raised my Mg from the low 1100's to 1250. I still have low Alk at 6.1dKH and CA is at 470. My other system has Mg at 1155, Alk at 7.7dKH and CA at 400. I like to dose slow rather than add the large amounts suggested by the calculators. I'll continue to work on it and try the two part when I'm out of Tech M. I'm also going to get some new test kits as well since these are a bit over a year old (Saliferts).

For my other additives, I use Turbo Calcium for increasing the CA in my new saltwater. I dose Ca in the tank with 400 Ca and I don't dose the other tank as it holds typically at 450 with no additives. I also have the Warner Marine 2 part and use that for daily Alk and Ca dosing.

[DaveJ]

Interesting thread.... and I want to get input that I think others may find useful, as I would.

When y'all talk about stability, please define that as ranges per day.

Ca - +/- x ppm
Alk - +/- x dKH or ppm
Mg - +/- x ppm


Let me tell you why this is important for me... when I hear stable, that means steady consistent levels. Calcium runs 420 all the time for example. Or Alk is 9.5 all the time....

However, in our tanks, that constant value is almost impossible. Daily dosing say 70ml of Alk solution (two part) is to offset the .3 or .4 drop in dKH (15-20 ppm) per day. If you do that all at once, its not 'supposed' to be hard on critters. .5 is generally the acceptable daily change amount. However, by having to dose to adjust that level back up to your 'ideal' value, its by definition not stable.

See what I am getting at?? So please define stable and put some values attached to it.

[Sk8r]

Mine used to swing 10 pts a day cal, alk pretty stable due to dosing buffer via topoff, and I still had good growth, good PE, not so great color. Well, rotten color. Ushio bulb, which is another issue.

Now with a kalk reactor, I'm staying right at 9.3 alk and 420 cal for weeks on end. I can say this supplementation works with a 54 g tank with small coral 'draw' on calcium. It remains to be seen how it holds up in conditions of more demand---also I don't know what the cutoff is between what kalk can do vs when you start needing a calcium reactor.

The swing didn't seem to hurt too much, however, just with acropora aculeus and particularly montipora species, and ac. valida. The bali slimer seemed to be a little less happy with it.

[chessmanmark]

I don't know how to insert a quote but I don't think this was responded to-
"Is a big flucuation in pH a problem for SPS corals or should it just be ignored and worry about alk calcium and magnesium(those are very stable right now)"

I think ph would be the first thing you need to test for and look at. I have most of my books in storage right now or I'd look up Anthony Calfo's quote on this. His point is so clear because of his eloquence. Now if I remember how he said it (not sure of the numbers involved), however his analogy on ph was the difference (perhaps in a point difference in ph?) was comparable to sitting on a nude beach in Miami naked and then instantly being transported to the frozen artic, still naked. Don't underestimate the importance of ph.

[Aquarist007]

<a href=showthread.php?s=&postid=10518252#post10518252 target=_blank>Originally posted</a> by Sara B
Dosing daily I have raised my Mg from the low 1100's to 1250. I still have low Alk at 6.1dKH and CA is at 470. My other system has Mg at 1155, Alk at 7.7dKH and CA at 400. I like to dose slow rather than add the large amounts suggested by the calculators. I'll continue to work on it and try the two part when I'm out of Tech M. I'm also going to get some new test kits as well since these are a bit over a year old (Saliferts).

For my other additives, I use Turbo Calcium for increasing the CA in my new saltwater. I dose Ca in the tank with 400 Ca and I don't dose the other tank as it holds typically at 450 with no additives. I also have the Warner Marine 2 part and use that for daily Alk and Ca dosing.

magnesium is not measured in any of the alkalinity tests nor is calcium so dosing with either isn't going to give you a higher pH

magnesium simply helps you maintain higher concentrations of calcium. I can't remember reading anywhere that corals or fish are affected by high or low or fluctuations in magnesium.

how is your pH---if low you could use kent reef boost--it will raise the alkalinity and the pH (I think it is due to the boron in it)
fluctuations in pH and alkalinity could affect the health of inverts.

[SaraB]

I do use a Salifert Magnesium test kit. I also run a Kalk reactor on both systems and drip with top-off water 24/7. The reactors stir the Kalk 4 times a day for 15 minutes at a time. I have a basement fishroom and my PH remains in the range of 7.8 to 8.0 as the A/C running all summer has an effect on it's level. In the fall and winter its more in the 8.2 range as I have a vent that's open for fresh air in the room.

[JB NY]

<a href=showthread.php?s=&postid=10518386#post10518386 target=_blank>Originally posted</a> by DaveJ
Interesting thread.... and I want to get input that I think others may find useful, as I would.

When y'all talk about stability, please define that as ranges per day.

Ca - +/- x ppm
Alk - +/- x dKH or ppm
Mg - +/- x ppm


Let me tell you why this is important for me... when I hear stable, that means steady consistent levels. Calcium runs 420 all the time for example. Or Alk is 9.5 all the time....

However, in our tanks, that constant value is almost impossible. Daily dosing say 70ml of Alk solution (two part) is to offset the .3 or .4 drop in dKH (15-20 ppm) per day. If you do that all at once, its not 'supposed' to be hard on critters. .5 is generally the acceptable daily change amount. However, by having to dose to adjust that level back up to your 'ideal' value, its by definition not stable.

See what I am getting at?? So please define stable and put some values attached to it.

First you need to understand that the test kits we use are not 100% accurate. A kit that costs under $50 is pretty good but I think that real labs use stuff that cost 10x what we pay. but mostly stable to me means that it is around the same. You should also get in the habit of testing around the same time. So if you test every day you should do it at the same time of day.

If had to give some +/- I would say

Alk +/- 0.5
Ca +/- 20
Mg +/- 30

Here are my records for about 1 1/2 years of taking monthly readings.


11/30/2003 Ca:430 Alk:10.2 Mg:1200
12/09/2003 Ca:420 Alk:10.2 Mg:1250
01/06/2004 Ca:415 Alk: 9.4 mg:1300
02/06/2004 Ca:440 Alk: 8.6 Mg:1200
02/17/2004 Ca:440 Alk: 8.4 mg:1350
03/20/2004 Ca:470 Alk: 8.4 Mg:1320
04/21/2004 Ca:460 Alk: 8.6 Mg:1350
06/23/2004 Ca:490 Alk: 7.7 Mg:1320
07/28/2004 Ca:470 Alk: 8.6 mg:1350
09/03/2004 Ca:480 Alk: 10.9 Mg:1390
10/07/2004 Ca:480 Alk: 10.6 Mg:1390
11/03/2004 Ca:550 Alk: 9.6 mg:1350
12/08/2004 Ca:470 Alk: 8.4 Mg:1320
02/06/2005 Ca:470 Alk: 7.7 Mg:1320



I started keeping my alk lower and Ca higher in Dec 2003. The spike in sept 2004 is from being lazy for the summer. But no problems happened because of it.

[Sk8r]

Thanks. When I said I had a 10pt swing on readings, stupid of me, I forgot a decimal. I'm no chemist; I also prove I'm no mathematician.

[Serioussnaps]

FWIW, your MG levels can drop somewhat faster in your system if you use alot of kalkwasser/lime. Just thought I would add that.

[SaraB]

<a href=showthread.php?s=&postid=10522530#post10522530 target=_blank>Originally posted</a> by Serioussnaps
FWIW, your MG levels can drop somewhat faster in your system if you use alot of kalkwasser/lime. Just thought I would add that.

Thanks, I did not know that was the case!

[Aquarist007]

<a href=showthread.php?s=&postid=10522203#post10522203 target=_blank>Originally posted</a> by JB NY
First you need to understand that the test kits we use are not 100% accurate. A kit that costs under $50 is pretty good but I think that real labs use stuff that cost 10x what we pay. but mostly stable to me means that it is around the same. You should also get in the habit of testing around the same time. So if you test every day you should do it at the same time of day.

If had to give some +/- I would say

Alk +/- 0.5
Ca +/- 20
Mg +/- 30

Here are my records for about 1 1/2 years of taking monthly readings.


11/30/2003 Ca:430 Alk:10.2 Mg:1200
12/09/2003 Ca:420 Alk:10.2 Mg:1250
01/06/2004 Ca:415 Alk: 9.4 mg:1300
02/06/2004 Ca:440 Alk: 8.6 Mg:1200
02/17/2004 Ca:440 Alk: 8.4 mg:1350
03/20/2004 Ca:470 Alk: 8.4 Mg:1320
04/21/2004 Ca:460 Alk: 8.6 Mg:1350
06/23/2004 Ca:490 Alk: 7.7 Mg:1320
07/28/2004 Ca:470 Alk: 8.6 mg:1350
09/03/2004 Ca:480 Alk: 10.9 Mg:1390
10/07/2004 Ca:480 Alk: 10.6 Mg:1390
11/03/2004 Ca:550 Alk: 9.6 mg:1350
12/08/2004 Ca:470 Alk: 8.4 Mg:1320
02/06/2005 Ca:470 Alk: 7.7 Mg:1320



I started keeping my alk lower and Ca higher in Dec 2003. The spike in sept 2004 is from being lazy for the summer. But no problems happened because of it.

very helpful--thanks
I am not clear on the symantics here-----I gather you are receiving accurate results monthly---but how often are you testing and dosing---I am using the same dosing chemcals as you stated you are using---once a week.
I have a reefing buddy--who uses the two part system and doses everynight --I was just tank sitting for the last week--he has two plastic cups with the lines marked on it for daily using and I think he monitors it once a week. personally I prefer to test and then dose----so to state a clear question to you:
If ph alk ca and mg are stable----do they remain stable for the week (taking into consideration that the two tanks I mentioned above are 10 and 8 months old)

[Aquarist007]

<a href=showthread.php?s=&postid=10522530#post10522530 target=_blank>Originally posted</a> by Serioussnaps
FWIW, your MG levels can drop somewhat faster in your system if you use alot of kalkwasser/lime. Just thought I would add that.

I am trying to grasp the chemistry here--I thought magnesium simple bonded with calcium so you could supersaturated calcium levels. I was under the impression that it was not used up in this process---and as a result ---once you got the magnesium levels up to 1300 or so then that level remained very stable.

[JB NY]

I test once a month. In the beginning I tested more often but for the last few years of the tank I only tested once a month. If something was really off I might test it 48 hours later to see if things got back on track.

I dose ca/alk through a ca reactor and kalk reactor so that is done all the time. The Ca reactor is on 24/7 and all top off water goes through the kalk reactor. Mg is only added to water change water. I do that once a week.

[Aquarist007]

<a href=showthread.php?s=&postid=10521969#post10521969 target=_blank>Originally posted</a> by Sara B
I do use a Salifert Magnesium test kit. I also run a Kalk reactor on both systems and drip with top-off water 24/7. The reactors stir the Kalk 4 times a day for 15 minutes at a time. I have a basement fishroom and my PH remains in the range of 7.8 to 8.0 as the A/C running all summer has an effect on it's level. In the fall and winter its more in the 8.2 range as I have a vent that's open for fresh air in the room.

very similar situation----is 7.8 the lowest it goes or is the kalk reactor set at this point. the reason I am asking because mine will drop over a week from 8.1 to 7.7---at that point I either use calcium hydroxide or buffers depending on the alkalinity level.
If I left it alone would it continue to fall or would introducing something so basic as opening the basement windows and or using an air stone help?

[Aquarist007]

<a href=showthread.php?s=&postid=10522871#post10522871 target=_blank>Originally posted</a> by JB NY
I test once a month. In the beginning I tested more often but for the last few years of the tank I only tested once a month. If something was really off I might test it 48 hours later to see if things got back on track.

I dose ca/alk through a ca reactor and kalk reactor so that is done all the time. The Ca reactor is on 24/7 and all top off water goes through the kalk reactor. Mg is only added to water change water. I do that once a week.

thanks I understand that--but in my situation where I have to dose by hand--would the water parameters be stable for weekly testing or should it be done everyother day etc?

[MJAnderson]

<a href=showthread.php?s=&postid=10522583#post10522583 target=_blank>Originally posted</a> by Sara B
Thanks, I did not know that was the case!

Well only indirectly.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1150068&highlight=kalk+and+mag

[JB NY]

<a href=showthread.php?s=&postid=10522904#post10522904 target=_blank>Originally posted</a> by capn_hylinur
thanks I understand that--but in my situation where I have to dose by hand--would the water parameters be stable for weekly testing or should it be done everyother day etc?

Once you have things so you are dosing the right amount. I don't think you should need to test more than once a week.

[SaraB]

<a href=showthread.php?s=&postid=10522889#post10522889 target=_blank>Originally posted</a> by capn_hylinur
very similar situation----is 7.8 the lowest it goes or is the kalk reactor set at this point. the reason I am asking because mine will drop over a week from 8.1 to 7.7---at that point I either use calcium hydroxide or buffers depending on the alkalinity level.
If I left it alone would it continue to fall or would introducing something so basic as opening the basement windows and or using an air stone help?

I don't run the Kalk reactors on a shut off/probe system at all. If it starts to dip lower than the 7.8, I know it's time to refill the Kalk/lime media and then the PH rises back up.

[Aquarist007]

<a href=showthread.php?s=&postid=10523048#post10523048 target=_blank>Originally posted</a> by Sara B
I don't run the Kalk reactors on a shut off/probe system at all. If it starts to dip lower than the 7.8, I know it's time to refill the Kalk/lime media and then the PH rises back up.

ok then--you are doing the same thing as me-- have you ever observed it following below 7.8

This is the problem in understanding I am having---if pH is lowering because of carbon dioxide conditions in the house then there should be a point where the carbon dioxide levels off in the house and concurrently in the tank so if you ignore the following co2 rate like some suggest it will start to come back up on its own.

[SaraB]

Yes, I have hit in the 7.7's and then added Lime to the reactor. The interesting thing is that I have 2 sump/fuge systems side by side in my fishroom and one has lower PH than the other. The one with the lower PH has the display tank located in the basement, so that's what I concluded to it having low PH with the Furnace in the basement... or a different Kalk Reactor not working as well as the other. The system with the higher PH, the tank is on the first floor. Also, both sump/fuge systems are in the basement as well in a 10x21 fishroom.

[Sk8r]

Rather than repeat what I've been told without quite understanding why it should be, I asked in the Reef Chemistry forum about these statements: 1. Dripping kalk may cause phosphate to precip out, and putting it right over your skimmer intake might help you bail some out; [generally good for corals] and 2. dripping kalk may cause mg to precip out. [can be a fixable problem for maintaining alk/cal.]

The initial respondent says yes, to a minor degree. The thread link is:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1181767

[MJAnderson]

<a href=showthread.php?s=&postid=10524061#post10524061 target=_blank>Originally posted</a> by Sk8r
Rather than repeat what I've been told without quite understanding why it should be, I asked in the Reef Chemistry forum about these statements: 1. Dripping kalk may cause phosphate to precip out, and putting it right over your skimmer intake might help you bail some out; [generally good for corals] and 2. dripping kalk may cause mg to precip out. [can be a fixable problem for maintaining alk/cal.]

The initial respondent says yes, to a minor degree. The thread link is:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1181767

Bertoni replied NO to the same question about Mag when I asked it after reading it in Randy's article.

[Serioussnaps]

<a href=showthread.php?s=&postid=10525053#post10525053 target=_blank>Originally posted</a> by MJAnderson
Bertoni replied NO to the same question about Mag when I asked it after reading it in Randy's article.

Well fiddlesticks.....Randy agrees with me because I see it HAPPEN IN MY SYSTEM.

[rynon]

I will admit I read most of this but not all so forgive me if this is in here. I've always tried to keep my alk at 10ish Dkh.....I find that everything does much better. I prefer to have my calcium on the low end. When my Alk got below 9 my Trach brain would not open during the day (not SPS I know). Since then I have tried to maintain my alk at a higher level.....also seems to keep any algae down (maybe the higher more stable Ph?). I JUST as of yesterday added a Kalk reactor so hopefully that will level everything out? I am sort of new to SPS but have never lost one......probably over 9 months or so....I have never seen RTN or STN. Just wanted to add my 2 cents.....also I have never tried higher calcium and lower alk for any period of time.

[Aquarist007]

<a href=showthread.php?s=&postid=10523459#post10523459 target=_blank>Originally posted</a> by Sara B
Yes, I have hit in the 7.7's and then added Lime to the reactor. The interesting thing is that I have 2 sump/fuge systems side by side in my fishroom and one has lower PH than the other. The one with the lower PH has the display tank located in the basement, so that's what I concluded to it having low PH with the Furnace in the basement... or a different Kalk Reactor not working as well as the other. The system with the higher PH, the tank is on the first floor. Also, both sump/fuge systems are in the basement as well in a 10x21 fishroom.

I don't think it is simply location of the furnace------
not all lowering of pH is strickly due to carbon dioxide levels in the tank. Also I think carbon dioxide problems in the house are a combination of air circulation and insulation. ---and carbon dioxide/ oxygen exchange occurs on the surface of the water of the tank besides in the sump/refugium and skimmer.
----and the hotter the room the more carbon dioxide it can hold

my eg here
--my sump and fuge are in the basement also--the main tank is in a small room at the front of the house. If I close the door to that room the circulation slows down and the temp really rises quickly due to the sun coming in the windows and the halides over the tank. You walk into that room after 15 min and it is very hot and the air is stiffling. Yet the air in the basement where the air conditioning is drawing from is cool and not hard to breathe---my pH in the main tank fluctuates over the entire week from 8.2-7.7.

I have a 30 gal quarantine/frag/reef tank(depending on the crisis) right beside my fuge and sump in the basement. The pH never ever moves---8.1 steady.

[SaraB]

Yes, the air is warm in the room during the summer as I shut off the incoming air vent from the outside that was installed. Illinois is hot and humid in the summer. I keep the door open just a crack, but it does not help the heat factor. My husband is into collectibles and if I dare rust his collections in the basement, I'm in BIG trouble. PH stays in the 8.1 to the high 8.2's when the air is not running and the outside vent is opened (spring, fall & winter)

[alazo1]

Since there seems to be some talk on this thread regarding ph I have a question.

How in the heck do you guys with a kalk reactor keep it stable?. I dose all top off with it at a drip rate and ph really fluctuates depending on how much kalkwasser I have in the reactor. Seems to keep it stable I'd have to add a certain amount every couple of days. If I add say a cup a month the ph swing from when it's added to when it's about 1/4 left is pretty dramatic (around 8.0 - 8.5).

thanks,
Albert

[Sk8r]

Bertoni came up with an interesting observation: if you are supplementing [an dI hope I'm quoting him right] with 2-part or Kent's or whatever, you're actually adding some mg.

If you are supplementing with kalk, you are not, because there is no mg in kalk.

So if the corals are using mg, and you are not supplying it via your supplement, the net effect is that you are losing mg and need to supplement more.

That may reconcile Randy with Bertoni. Bertoni makes those comments in the thread I linked to above.

[GSMguy]

is there a diagram anywhere showing the propper setup for a kalk reactor?

[rynon]

I just got one yesterday....now you have me worried. It said to add 2 coffee cup of kalk...that seemed insane to me so I added 12 teaspoons...should be enough for a week. Anyway I'll be paying attention to this to see what everyone does with their kalk reactor.

[Sk8r]

Basically, you just route your topoff through one hose and it comes out into your tank via the other. The stirrer is the only moving part, and it just keeps it kicked up a bit.

[rynon]

Yes I understand that. My problem is knowing how much to add to the reactor.....2 COFFEE CUPS!!!!! That just seems insane to me? Right now my reactor is stirring nothing...all the kalk is on the bottom but the alk is WAY over 16 dkh so it's working, my tap is 0 after RO/DI filter. I feel I've hijacked this......sorry. 2 CUPS of KALK....GEEZ.

[JetCat USA]

the effluent in the reactor will only hold so much lime in solution (saturation) and then the rest of the 2 cups you added will settle to the bottom of the reactor, as water is pushed through to the tank and the saturated water is diluted with the new water entering the reactor the mixer kicks in ever so often and keeps the effluent saturated and the process repeats till the Kalk is completely depleted.

[rynon]

Ahhhh, thank you so much that helps a ton. From now on I'll just "dump" the kalk in. Really thank you a LOT. The instructions did not help, plus they installed the check valve in backwards....haha, I had some water spraying for a bit.

[JetCat USA]

i don't know how your instructions are setup but put the check valve on the water inlet, not the outlet, the lime will clog it up.

[rynon]

yeah, um, no water in, no water out....it was fairly easy to figure out. I went with a cheaper brand.....I guess I paid for it....althought it was very simple to fix. It's a AquaMedic 1000, water inlet goes through a tube to the bottom of the reactor, water sprays out of the INLET...yeah, not right. I did the "blow" test on the valve....it was backwards. It seems to be working correctly. Super slow stirring, water clearish on top, water on bottom is milky? Anyway testing the topoff coming through the reactor helped a lot.....I KNOW it's got a lot of kalk in it. Thanks a LOT for your help...really appreciated....sorry for all the ..... bad habbit :)

[GSMguy]

so my osmolator in ATO resevoir pump pumps water into the kalk reactor causing kalk water to be forced up and out of the reactor and into the tank?

[JetCat USA]

Yeap.

be sure you use a check valve with the Osmolator, their pumps don't last to long with any Kalk backwashing into them.

[TwistedTiger]

Given that the questions discussed here and in the other threads, (lighting, alk/calc/mag and water quality) are asked over and over in numerous threads, wouldn't it benefit everyone to make these threads a sticky so they stay at the top of the page? Many many threads could be eliminated by putting these threads in a place where everyone would see them before they ask the same question for the millionth time. Thanks JB NY for starting them, they have really been some good reads and discussions.

[Sk8r]

I put in half a pound of kalk once a month. I use a Hanna stirrer, and have recalled something I knew when I worked in a lab: you might as well have the 'hood' liftable [screws taped to the cord, for safe storage] because as the stuff changes viscosity due to depletion, the stirrer-magnet can get cranky or even stall and bog the stirrer rod down in kalk sludge, so it is rather like glue and not being stirred as it ought. This is the stirrer's fault. If this happens to a Hanna, do not hesitate a heartbeat about taking the hood off and letting it run on your kitchen table until it has gotten its speed back up. Then you can usually put the hood back on, install it, and get it going again quite nicely. They're great stirrers and practically indestructible, but they do have that quirk.

For anybody keeping sps in a 54, I heartily recommend a kalk reactor: from daily fussing and rise and fall of alk/cal, I've gone to once to twice a month fussing. Life is good.

[GSMguy]

Sk8r im going with the GEO kalk reactor thanks for all the help

[Aquarist007]

I am at the stage where I need to add kalk to stablilize my pH.
Can this by added by hand or do you need to set up a drip. So far I have been able to keep alkalinity, calcium and magnesium stable by following Randy's article and dosing by mixing myself.

[JetCat USA]

I've used the Kalk Slurry on systems i don't have a reactor on for the past 4 yrs, beats the heck out of dripping and even on systems with a CaCO3/CO2 reactor i use the slurry once in a while to kick pH back up.

[alazo1]

Do you folks with a kalk reactor have the mixer running while dripping?. Mine turns on for a minute every hour (forgot the brand). I get a lot of fluctuation in ph depending on how much kalk I have in there. I'm thinking I should turn the timer off while dripping to prevent ph flucs, what do you think?.

Albert

[JetCat USA]

the mixer turns on at set times for a set length of time each day, when the system evaporates to the point that the top off system kicks it on is a game of chance so sometimes you get clear saturated additions, sometimes not so clear.

[GSMguy]

well my aditions are never clear with my current system because in the ATO container it stirs constantly

i willing to take the chance with the reactor but i might not waste my time hooking it to my aquacontroller i might just use a round light timer on for 4 or 5 15 minute periods during the day.

[Aquarist007]

<a href=showthread.php?s=&postid=10541666#post10541666 target=_blank>Originally posted</a> by JetCat USA
I've used the Kalk Slurry on systems i don't have a reactor on for the past 4 yrs, beats the heck out of dripping and even on systems with a CaCO3/CO2 reactor i use the slurry once in a while to kick pH back up.

is Kalk Slurry a brand name?

[JetCat USA]

No it's the way you add the Kalk to the system. you determine your tanks daily demands and the amount of Kalk that will meet those demands (takes some testing to get both those), then you add that amount of Kalk to about 16oz of RO/DI water, slurry it around till it's all mixed up and dump it directly into the tank in a high flow are. some people dump it down an overflow, some in the sump, i have the highest flow inside the tank its self so that is where i pour it.

allot of people used to second guess it claiming any impurities from the Kalk made it to the tank, but Anthony Calfo was the one who introduced the slurry to me and i talked with him in great detail about the whole thing, he's used it forever and a day and never had a problem out of it. tried it for a while on one of my systems with beyond my expectation results so it's what i use on systems now that don't have such a demand to make it impractical. the limit is you can't add such an amount in a single dose to raise the tanks overall pH more then 0.2 points. you don't go by the initial spike either, let it circulate an hour or so and settle in, I've had initial spikes on my 180 that used to be onward of a full point in pH but it quickly settled down.

you can do multiple doses, but i keep it down to a single dose, dumped in a few hours after lights out as pH is starting to naturally decline. if I've got such a high demand that the single dose doesn't work, i put a CaCO3/CO2 reactor on and use the slurry for the occasional pH kick in the pants :)

if you don't want to deal with nightly 30 seconds and you're done dosing then the Kalk reactor will automate it.

[Aquarist007]

<a href=showthread.php?s=&postid=10542945#post10542945 target=_blank>Originally posted</a> by JetCat USA
No it's the way you add the Kalk to the system. you determine your tanks daily demands and the amount of Kalk that will meet those demands (takes some testing to get both those), then you add that amount of Kalk to about 16oz of RO/DI water, slurry it around till it's all mixed up and dump it directly into the tank in a high flow are. some people dump it down an overflow, some in the sump, i have the highest flow inside the tank its self so that is where i pour it.

allot of people used to second guess it claiming any impurities from the Kalk made it to the tank, but Anthony Calfo was the one who introduced the slurry to me and i talked with him in great detail about the whole thing, he's used it forever and a day and never had a problem out of it. tried it for a while on one of my systems with beyond my expectation results so it's what i use on systems now that don't have such a demand to make it impractical. the limit is you can't add such an amount in a single dose to raise the tanks overall pH more then 0.2 points. you don't go by the initial spike either, let it circulate an hour or so and settle in, I've had initial spikes on my 180 that used to be onward of a full point in pH but it quickly settled down.

you can do multiple doses, but i keep it down to a single dose, dumped in a few hours after lights out as pH is starting to naturally decline. if I've got such a high demand that the single dose doesn't work, i put a CaCO3/CO2 reactor on and use the slurry for the occasional pH kick in the pants :)

if you don't want to deal with nightly 30 seconds and you're done dosing then the Kalk reactor will automate it.

thanks Jetcat---I'm used to mixing my own so this method is just what I am looking for.

[gary faulkner]

The method I use:
Empty 5 gal bucket, add 1 TBL Mrs. Wages, add 3 Gal RODI, let sit overnight, dose 1 gal per day of the clear liquid into sump for top off. I use this with a Cal. reator also.

Works for me.

[Aquarist007]

<a href=showthread.php?s=&postid=10544904#post10544904 target=_blank>Originally posted</a> by gary faulkner
The method I use:
Empty 5 gal bucket, add 1 TBL Mrs. Wages, add 3 Gal RODI, let sit overnight, dose 1 gal per day of the clear liquid into sump for top off. I use this with a Cal. reator also.

Works for me.

what is Mrs. Wages --is it something I have to go over the river for and sneak back to Canada :) :)

[GSMguy]

mrs wages is kalk you can buy at the grocery store aka pickling lime

[Aquarist007]

<a href=showthread.php?s=&postid=10546205#post10546205 target=_blank>Originally posted</a> by GSMguy
mrs wages is kalk you can buy at the grocery store aka pickling lime

thanks appreciated---oh I guess you eat the pickles first :rolleyes:

sorry I'm been serious all day--maybe I should take a trip to the lounge.

[GSMguy]

<a href=showthread.php?s=&postid=10546245#post10546245 target=_blank>Originally posted</a> by capn_hylinur
thanks appreciated---oh I guess you eat the pickles first :rolleyes:

sorry I'm been serious all day--maybe I should take a trip to the lounge.

about to send you a PM...

[DocG]

Capn,

You have to go over to the states and sneak it back into Canada. You cannot buy pickling lime in Canada.

I have used the slurry method for a while now. On a system with 450 gallons of water I add one or two teaspoons of kalk in a 1 litre jug and stir it up really well and dump it into the high flow area of the sump. On my system the 1-2 teaspoons a day (not every day but more often then not) does not really affect the Calcium or alkalinity levels at all but it does keep the pH from dipping under 8.0 and generally keeps the pH more stable, which is why I started doing it.

[TwistedTiger]

<a href=showthread.php?s=&postid=10547659#post10547659 target=_blank>Originally posted</a> by DocG
Capn,

You have to go over to the states and sneak it back into Canada. You cannot buy pickling lime in Canada.

Can't you just order calcium hydroxide from two parts? It's pretty cheap. http://www.twopartsolution.com/index.php?main_page=index&cPath=10&zenid=91a026d4dcbf8a844864decc6ee46a02

[Aquarist007]

<a href=showthread.php?s=&postid=10549040#post10549040 target=_blank>Originally posted</a> by TwistedTiger
Can't you just order calcium hydroxide from two parts? It's pretty cheap. http://www.twopartsolution.com/index.php?main_page=index&cPath=10&zenid=91a026d4dcbf8a844864decc6ee46a02

when I asked my supplier he convinced me not to use kalk without dripping--said it was messy and easy to error?
After talking to you guys --I don't see a problem with this?

[TwistedTiger]

<a href=showthread.php?s=&postid=10549526#post10549526 target=_blank>Originally posted</a> by capn_hylinur
when I asked my supplier he convinced me not to use kalk without dripping--said it was messy and easy to error?
After talking to you guys --I don't see a problem with this?

I've been using mine with an auto topoff for about 3 years with no problems. Much much easier than dripping and much more consistent. Just make sure you use an auto topoff system that adds small amounts at a time.

[JetCat USA]

<a href=showthread.php?s=&postid=10549526#post10549526 target=_blank>Originally posted</a> by capn_hylinur
..........said it was messy and easy to error?


it's messy if you're so inclined to slosh the heck out of it when making up a slurry, 99% of people are capable of doing it with minimal to no mess at all and if you test your system, find the proper dose and then add that much it's no different then any other additive/supplement you add to the system 99% of people are talented enough to do that as well, i guess your supplier is that 1% :)

[Aquarist007]

<a href=showthread.php?s=&postid=10549546#post10549546 target=_blank>Originally posted</a> by JetCat USA
it's messy if you're so inclined to slosh the heck out of it when making up a slurry, 99% of people are capable of doing it with minimal to no mess at all and if you test your system, find the proper dose and then add that much it's no different then any other additive/supplement you add to the system 99% of people are talented enough to do that as well, i guess your supplier is that 1% :)

thanks--I'll start using it---he knows I am a chemistry/biology teacher----we only slosh the heck out of our tim hortons coffee :)

[TwistedTiger]

<a href=showthread.php?s=&postid=10549546#post10549546 target=_blank>Originally posted</a> by JetCat USA
99% of people are talented enough to do that as well, i guess your supplier is that 1% :)
Or could it be that I just bought 4.5 pounds of kalc for $9.99 which should last me well over a year and there is more profit to be made from other alk/calc supplements?:lol2: :lol2: :lol2:

[JetCat USA]

With the advent of the internet and a computer connected to it in most homes these days LFS owners who consistently give poor advice will find that their margin of profit would be much higher if they actually gave educated advice rather then discouraging their customers to the point they take their business elsewhere.

I'm sure if capn's supplier had been so kind as to say "Yeah, that Kalk stuff works just as good as any other additive, it can be messy and you need to be careful getting the right dose", he'd of bought some that day

[Aquarist007]

<a href=showthread.php?s=&postid=10549764#post10549764 target=_blank>Originally posted</a> by JetCat USA
With the advent of the internet and a computer connected to it in most homes these days LFS owners who consistently give poor advice will find that their margin of profit would be much higher if they actually gave educated advice rather then discouraging their customers to the point they take their business elsewhere.

I'm sure if capn's supplier had been so kind as to say "Yeah, that Kalk stuff works just as good as any other additive, it can be messy and you need to be careful getting the right dose", he'd of bought some that day

actually he is a mail order supplier--not live fish---and one of the guys I trust---maybe he doesn't trust me cause of the coffee stains on my shirts _LOL

LFS---that's a hole ball of worms---criticism of them got me in hot water with my local reef site. I don't know if I should get into that here say I agree 200 per cent what you said above.---and I have learned the value of a guarantine tank for many reasons.

[five.five-six]

ok, I use my ACIII to pump my kalkwasser at 8.13. after messing around with the sump fan speed and the lower limit ph I have gotten it to about match evaporation at 5 gal ~3.5 days. currently I am adding iodine to the kalkwasser. is there any reason I can not add Mg to the kalkwasser. ie: test, do the chart, add X amount of mg to kalkwasser, test again in 3 days? or can I just dump it in my sump..

[The Reefer91]

i have a question. if you use a calcium reactor without a pH monitor and simply have it on a timer, is there anything else you should be supplementing, like randy's two part?

sorry if it's a dumb question.

[TwistedTiger]

<a href=showthread.php?s=&postid=10580213#post10580213 target=_blank>Originally posted</a> by The Reefer91
i have a question. if you use a calcium reactor without a pH monitor and simply have it on a timer,

Are you talking about running the CO2 on a timer? If so that's not a good idea IMO. Without a controller you just need to set your bubbles count and drip rate at a reasonable rate for your tank volume and then test ALK/Calc daily until you get it set where you need it.

As far as a PH monitor you should have some way to check PH in a reef tank even if you are not running a calcium reactor, but neither a ph controller or a ph monitor are required equipment for a reactor.

[The Reefer91]

wait, but wouldn't that mean i would need to continously run the reactor? or would the CO2 just pool up inside the reactor?

[TwistedTiger]

<a href=showthread.php?s=&postid=10580329#post10580329 target=_blank>Originally posted</a> by The Reefer91
wait, but wouldn't that mean i would need to continously run the reactor? or would the CO2 just pool up inside the reactor?
A calcium reactor is a continuous operation piece of equipment.

[TwistedTiger]

Try this article and see if it helps you any.

http://www.reefkeeping.com/issues/2002-05/sh/feature/index.php

[The Reefer91]

thanks! :)

[apbt217]

My Calcium levels are pretty steady anywhere from 425-455ppm, my Alkanity is running pretty high dKH 14 (is this bad) and my Magnesium is at 1350ppm. I'm topping off with R/O water trying to get the dKH to come down a bit and I heard that with higher Mag levels you get better Coraline growth? Is there any truth to that?

[apbt217]

My Calcium levels are pretty steady anywhere from 425-455ppm, my Alkanity is running pretty high dKH 14 (is this bad) and my Magnesium is at 1350ppm. I'm topping off with R/O water trying to get the dKH to come down a bit and I heard that with higher Mag levels you get better Coraline growth? Is there any truth to that?

[JB NY]

<a href=showthread.php?s=&postid=10595648#post10595648 target=_blank>Originally posted</a> by apbt217
My Calcium levels are pretty steady anywhere from 425-455ppm, my Alkanity is running pretty high dKH 14 (is this bad) and my Magnesium is at 1350ppm. I'm topping off with R/O water trying to get the dKH to come down a bit and I heard that with higher Mag levels you get better Coraline growth? Is there any truth to that?

14 dKH is a little high. I try to run it around 8.

Topping off with r/o water is what you should be doing. You need to stop dosing to get your alk down.

I did not notice any change in coralline growth when I had higher mg levels.

[Aquarist007]

<a href=showthread.php?s=&postid=10597033#post10597033 target=_blank>Originally posted</a> by JB NY
14 dKH is a little high. I try to run it around 8.

Topping off with r/o water is what you should be doing. You need to stop dosing to get your alk down.

I did not notice any change in coralline growth when I had higher mg levels.

the question becomes--why is your dkH so high-----
Are you using buffers to control your pH----- most contain boron which will up your dkH readings.

[MJAnderson]

<a href=showthread.php?s=&postid=10551601#post10551601 target=_blank>Originally posted</a> by five.five-six
ok, I use my ACIII to pump my kalkwasser at 8.13. after messing around with the sump fan speed and the lower limit ph I have gotten it to about match evaporation at 5 gal ~3.5 days. currently I am adding iodine to the kalkwasser. is there any reason I can not add Mg to the kalkwasser. ie: test, do the chart, add X amount of mg to kalkwasser, test again in 3 days? or can I just dump it in my sump..

One of the nice (or not so nice) things about Kalkwasser is that several heavy metals precipitate out of a solution with a PH of 12.4 (2 tsb per gallon of RO). Mag is one of them. Whatever you add will just end up in the bottom of the bucket (assuming you let it settle and just add clear limewater. A quote from Randy:

"Regardless of how much magnesium is present in the limewater to begin with, it will nearly all precipitate from solution, and clear limewater is not a source of magnesium for an aquarium. "

From this article:

http://www.advancedaquarist.com/issues/may2003/chem.htm

I can't find it now, but one of Randy's articles talked about what you can dose in kalk. I THINK one of them was Strontium.

[dheinze]

Hi all, I just skimmed through this so sorry if this question has already been asked. My alk is low (about 1.6 meq/L), and I want to raise it with baking soda. How fast can I change the alk and not stress my corals? FYI, I run kalkwasser in the ATO for balanced sumplement; I got into this (low alk) situation by dosing only calcium early on in my reefing career.

[Aquarist007]

<a href=showthread.php?s=&postid=10602333#post10602333 target=_blank>Originally posted</a> by dheinze
Hi all, I just skimmed through this so sorry if this question has already been asked. My alk is low (about 1.6 meq/L), and I want to raise it with baking soda. How fast can I change the alk and not stress my corals? FYI, I run kalkwasser in the ATO for balanced sumplement; I got into this (low alk) situation by dosing only calcium early on in my reefing career.

what's your pH, calcium and magnesium at?

[dheinze]

Since I use kalk, my pH runs on the high side~8.4; Ca at last test was 425ppm, and I have yet to test Mg (no test kit right now).

[Aquarist007]

Imo---do a few water changes and see if this brings back the normal seawater chemistry.

[dheinze]

hmm...I do about 10% wc weekly; I guess I thought this would've caught up with the alk situation sooner than it has (a couple months and running here). Maybe I will do an alk test on my freshly made up seawater (I use seachem reef salt), and see where that is.

[melev]

This thread has been nominated for Thread of the Month. You can vote for it in this poll:
http://reefcentral.com/forums/showthread.php?s=&threadid=1193958

[KurtsReef]

I have only recently started too keep SPS and feel as though I need to relearn all the chemistry aspects of reef keeping again. Coming from the much simpler world of soft corals, my routine simply did not include testing for many things and my system ran quite well...

Now with a larger system, attempting too keep more difficult items such as SPS I have been re-reading and reading articles/books getting back up to speed and had forgotten how complex this can be.

Tested Mg for the first time yesterday and it came in at 1050ppm so will be trying to raise that too the 1300 mark in the next few days using Bionic's Mg suppliment.

I have been using the Bionic two part since before beginning the larger reef system, but now own a calcium reactor I just need to set up and dial in. Plan on still using the two part in addition too that as the Ca reactor is more than likely not large enough.

There was mention of Mg (low Mg) in a system effecting the color of your SPS...I am very new too SPS, however noticed after picking up a frag of staghorn coral from a LFS which appeared too be very brown in the store that after being in my system for a couple of weeks it now has very purple tips and a more light color too its main body...not sure what caused the welcome color change however want too keep that kind of success going as well as obtain good growth. I only have 4 frags of SPS right now and all seem too be doing well.

[Aquarist007]

<a href=showthread.php?s=&postid=10642004#post10642004 target=_blank>Originally posted</a> by melev
This thread has been nominated for Thread of the Month. You can vote for it in this poll:
http://reefcentral.com/forums/showthread.php?s=&threadid=1193958

I am torn between this and the misconceptions thread--how many votes do we have?

[five.five-six]

<a href=showthread.php?s=&postid=10602010#post10602010 target=_blank>Originally posted</a> by MJAnderson

I can't find it now, but one of Randy's articles talked about what you can dose in kalk. I THINK one of them was Strontium.

well it appears to be fairly common practice to add iodine to Kalk, from what I understand strontium is not all that critical for a successful tank... I do not even test for it. should I?

as for the thoughts of your anemone, they are like women, no one understands why they do what they do.. if it can find just the right light and flow, and especially if it can get it's entire foot inside a hole, it may stay put for several years and then just get up and sting your favorite frag :(

[Aquarist007]

<a href=showthread.php?s=&postid=10649673#post10649673 target=_blank>Originally posted</a> by five.five-six
well it appears to be fairly common practice to add iodine to Kalk, from what I understand strontium is not all that critical for a successful tank... I do not even test for it. should I?

as for the thoughts of your anemone, they are like women, no one understands why they do what they do.. if it can find just the right light and flow, and especially if it can get it's entire foot inside a hole, it may stay put for several years and then just get up and sting your favorite frag :(

IMO dosing with either of them is not necessary if you are doing routine water changes.

I am not commenting on the other thought about the anenome----my wife reads these posts from time to time.:)

[chessmanmark]

This post is getting lost now. 11 pages back to find it today. Any chance of making this one a sticky JB?

[JB NY]

Like that? ;)

[JetCat USA]

Good threads don't need stickied :D

[chessmanmark]

Thanks, now I don't have to work so hard searching for it. Good info, such as that delivered in this thread, should be readily available.

[cutegecko3]

ive tried running high alk. and lost bright colored tips on my acros. so i keep mine at natural seawater level,and calcium at least 400.never tested for mg. im just learing what role that plays.

[gary faulkner]

OK to talk about types of media for reactor?

I need to order some and was using ARM. It seems to turn to mush too easily. Wondered if I should try some larger media?

Hope this isn't a hijack!

[JetCat USA]

the small grain ARM will only turn to mush if the reactor pH is driven to low either by operator error or the recirculation flow becoming restricted. correcting that problem will prevent the mudding, going to the larger media will help with any recirculation problems but will also mud if the low pH is operator error. and to keep on track, once mudded the media regardless of name brand will not supply Ca/Alk to the system. on a side note, ARM IME is the best at keeping Sr levels in check.

[MCsaxmaster]

Just a couple of comments on magnesium as I'm not sure these questions were completely addressed (appologies if I missed it).

Magnesium is important in a conversation like this because it forms ion pairs with carbonate in sea water (and bicarbonate). Calcium carbonate is substantially supersaturated in sea water (on the order of 300 - 400% typically) and we can easily raise that to 600%+ by maintaining higher alkalinity in captivity. We'd predict that calcium carbonate should spontaneously precipitate, since there's way more of it dissolved in the water than there "should" be. However, that's not what happens. One of the reasons is that magnesium forms those ion pairs with carbonate, making it more difficult for calcium carbonate (solid) to form and precipitate. In addition, magnesium carbonate tends to precipitate out with calcium carbonte during abiotic precipitation. Magnesium carbonate doesn't fit into the crystalline structure of calcium carbonate (whether that is CaCO3 as aragonite, calcite, or even amorphous CaCO3). That tends to discourage further precipitation. So, magnesium really gets in the way of calcium carbonate precipitation and allows CaCO3 to remain supersaturated.

Magnesium is extremly abundant in sea water. Yes, Mg is an imporant nutrient for any cell, but cells use so little Mg in their normal biology that it is essentially a drop in the ocean. Magnesium does also precipitate with calcium carbonate though, and calcifying organisms like corals, coralline algae, etc. consume it (just like they consume calcium). However, corals, which produce aragonite, consume Mg very, very slowly. Corals consume about 19 moles Ca for every 1 mol Mg. Magnesium is also about 3 times as concentrated as calcium in normal sea water. Thus, the Mg is 3X the conc. of Ca and gets used by corals at ~1/19th the rate. Very modest replenishment of Mg will easily replace what is lost to coral calcification.

On the other hand, coralline algae produce high magnesium calcite. This is a structurally different form of calcium/magnesium carbonate as compared to aragonite, it is more soluble, and has much more Mg. Typically coralline algae have Ca:Mg stoichiometry in the neighborhood of 4:1, not 19:1 as with corals. Coralline algae consume Mg proportionally much faster than corals, though coralline algae also tend to calcify a lot slower than corals. A lot of coralline algae growth can consume a fair amount of Mg, however.

Some salts do tend to be deficient in Mg as well, leading to problems from the get-go.

Recent evidence suggests that strontium is probably incorporated into the skeletons of calicifying organisms (as is lead, uranium, cadmium, etc.) simply as an impurity. The organisms are not necessarily going to any effert to put these into the skeletons--they end up there just because they get precipitated along with everything else. Magnesium, no the other hand, has very particular distribution patterns in coral skeletons, so it looks like the corals might really be "doing" something with the Mg, though nobody has a clue what that something might be.

Chris

[MCsaxmaster]

Also, just a note on alkalinity:

There are two definitions you'll typically run into for what total alkalintiy is. One tends to be preferred by oceanographers while the other tends to be preferred by analytical chemists (and both get used by chemical oceanographers ;)). The two are not mutually exclusive, but two different perspectives of the same property.

The oceanographic definition, which is not really useful to aquarists, is as follows (my wording)

Total alkalinity: the difference in concentration (molar or molal) between strong cations (+ ions) and strong anions (- ions) in sea water. Here "strong" means strong electrolytes (i.e., they completely dissociate).

While this is most certainly an appropriate definition, it isn't conceptually very useful for us.

A definition used by analytical chemists is more useful to us:

Total alkalinity: the excess concentration of proton acceptors over proton donors in sea water, determined when a sample is titrated to the carbonic acid endpoint. Expressed as the equivalent concentration of HCl necessary to reach the endpoint.

So, the total alkalinity is the concentration of everything that will buffer against a drop in pH (bicarbonate, carbonate, borate, phosphates, etc.) minus everything that will buffer against a rise in pH (free H+, HSO4-, etc.). The total alkalinity is the concentration of H+ that all the little bases can neutralize.

In sea water ~96% of the alkalinity is provided by the carbonate system, that is, by bicarbonate and carbonate ions. Of this 96% about 88% of the buffering is due to bicarbonate and about 12% is due to carbonate. Of the 4% of total alkalinity that is not provided by the carbonate system, most of it is provided by borate (~4%). Ions like phosphates, silicate, etc. also provide alkalinity, but they are usually so low in concentration compared to everything else that they don't make much of a difference in the context we're talking about (very important in porewater in sediments, or near hydrothermal vents, for example).

Corals and other calcifying organisms build skeletons out of some form of calcium carbonate. Since most of the alkalinity in sea water is provided by the carboante system (96%) we use total alkalinity as an indicator for how much bicarbonate and carbonate there is. Most critters probably use bicarbonate and transform it to carbonate at the site of calcification, but that step is unimportant here. This is why we want to always make sure that we use alkalinity supplements based on bicarbonate/carbonate and not something like borate. Borate will provide alkalinity, but not alkalinity that is useful to calcifying organisms.

Chris

[JB NY]

Good stuff Chris. Thanks for that contribution.

[Aquarist007]

I like your writing style--chris--technical but not too technical--start working on a book if you haven't already.
Scott

[Aquarist007]

I have read or been told that under certain conditions--low calcium high magnesium that corals will use magnesium and combine with the carbonates---to calcify ???

[Aquarist007]

Is kent super DKH---a non borate ph/alkalinity booster? If not what would you recommend--other then dosing with Kalk

[MCsaxmaster]

Good stuff Chris. Thanks for that contribution.

No worries :thumbsup:

I like your writing style--chris--technical but not too technical--start working on a book if you haven't already.

Ha, thanks! :D I'll get things written in a larger format someday. For now life is just too busy to do much more than magazine articles/reef club presentations.

I have read or been told that under certain conditions--low calcium high magnesium that corals will use magnesium and combine with the carbonates---to calcify ???

They always use Mg when they calcify, just not very much (very, very small portion of what is available). I suppose it is possible that they might increase use of Mg when Ca is low, but given recent findings I'd be skeptical of this. Of course, ya never know until you try it, and I don't believe anyone has ever done that.

Is kent super DKH---a non borate ph/alkalinity booster? If not what would you recommend--other then dosing with Kalk

That should be fine to use. It is most likely just a mix of sodium bicarbonate with a little sodium carbonate. Seachem's buffer (I forget the name) has a lot of borate in it, which can lead to problems. Honestly, considering how cheap sodium bicarbonate is relative to most salts, I don't know why any company would rely on borate alkalinity, but anyway....

If you need to boost just alkalinity I'd use either baking soda (sodium bicarbonate) or baked baking soda (sodium carbonate) as per Randy Holmes-Farley's articles on the subject. It's extremely cheap, and does exactly the job we want. Since it's intended for human consumption, it's probably as pure as any product we could buy (though not as pure as like reagent or analytical grade sodium bicarbonate intended for lab use).

cj

[sdoggssf]

Hey everybody, Sorry if this question has already been asked but i was wondering how to lower DKH? My DKH is around 16.0 and my CA is at 420, fortunatly all my corals have great color. However, with my DKH being so high i know there has to be some improvement if it is lowered. Does anyone have any advice?

[melev]

First thing I would do is get someone with some test kits to verify that those results are accurate.

If they are truly that high, stop dosing anything (two part buffers, kalkwasser, calcium reactor) for now, and do a 25% water change.

[Aquarist007]

<a href=showthread.php?s=&postid=10907557#post10907557 target=_blank>Originally posted</a> by sdoggssf
Hey everybody, Sorry if this question has already been asked but i was wondering how to lower DKH? My DKH is around 16.0 and my CA is at 420, fortunatly all my corals have great color. However, with my DKH being so high i know there has to be some improvement if it is lowered. Does anyone have any advice?
running high alk level you take the chance of some rapid precipitation of carbonates and or rapid corraline algae growth.
Either way that will consume carbonates and indirectly affect coral growth

[Aquarist007]

------I agree with melev----20- 25 per cent water change and bring it down to around 10.5 dKH

[JB NY]

Easiest way to bring your alk down is to only dose calcium for a while. Just check your alk every few days, you will notice that the alk seems to drop more than the Ca. Meaning, you might notice your alk drop 1-2 points before you see you calcium drop much at all. just dose some turbo calcium or some other calcium only additive (to keep the calcium levels stable) until the alk is where you want it, then re-start your normal dosing routine.

[Aquarist007]

for future consideration-----while your alk is falling :)

what is your pH----did you or are you dosing with a buffer---alot contain boron which can raise your alk levels very high.

[sdoggssf]

Thanks for the imput guys, i really appreciate it.

[Joyt]

Nice thread.

Need some help from expert advise
tank size 120 gal

I'm currently dosing Randy's receipe 1 for my SPS tank
Kh 50ml - 2 hrs once start from 12am (eg. 12am, 2am, 4am ...)
Ca 90ml - 2 hrs once start from 1am (Eg. 1am, 3am, 5am....)
each dosing amount will last 55mins and 5 mins rest before the next one started (about 7drops or so every 20sec estimated)
Total dosing amount at night Kh 350ml ca700ml

Mg 300ml every 3 days once at 7pm

Every night measure at 9.00pm Ca 400-420, kh 8.0-8.4 Mg 1280-1320

i struggled for almost 2 weeks before i manage to get this result due to ionic imbalance

Recently, PH drop significantly after switching all the dosing after lights off. Now (8.0-8.3) before was (8.2-8.5). I'm contemplating to slowly adjust back to 8.1-8.4 by delaying the dosing starting from 4am instead of 12am.

I'm very keen to know
1) Is there any way to measure the highly concentrated dosing solution using our test kit.
2) I don't know why but i need to dose a lot more ca solution than kh - i'm worry. Is it because CA precipitate causing more solution required when dosing?
3) what is the safe dosing amount/qty quantity within an hour ?

Hope someone can share his experience. Thanks
:) :)

[melev]

Joyt,

[welcome]

Why are you dosing so frequently? It appears you are dosing every two hours?

It sure sounds like you are dosing more than is necessary for a 120g tank, but when I was dosing, it was with B-Ionic.

[Wonder]

wrong post

[MCsaxmaster]

For measuring the concentration of the solutions you could do a 50 or 100 fold dilution (or whatever dilution you'd like to) and measure the concentrations. Make sure you're as accurate as possible in diluting, otherwise your calculated values will be off.

A possible and perhaps likely reason that the you need to use more of the calcium solution is that the actual calcium concentration is lower than calculated value due to hydration of the calcium chloride. Calcium chloride picks up water very, very easily (used as a dehydrant in some applications because it sucks up water so easily). This means that you may have mixed up a more dilute solution than you intended because much of the mass/volume of the salt was actually just water.

That does seem like a lot of dosing, so I'd be suspicious that a lot of what you're adding is precipitating abiotically. How exactly are you adding these solutions?

cj

[JetCat USA]

<a href=showthread.php?s=&postid=10941515#post10941515 target=_blank>Originally posted</a> by MCsaxmaster
........That does seem like a lot of dosing.......


He might have a huge pair of Gigas in there :D

[Aquarist007]

<a href=showthread.php?s=&postid=10941634#post10941634 target=_blank>Originally posted</a> by JetCat USA
He might have a huge pair of Gigas in there :D

lol I had to look this one up--for other duh"s like myself they are giant clams

http://animaldiversity.ummz.umich.edu/site/accounts/information/Tridacna_gigas.html

[MCsaxmaster]

"One point twenty-one gigawatts?! One point twenty-one gigawatts!?!" :D

[Joyt]

<a href=showthread.php?s=&postid=10941515#post10941515 target=_blank>Originally posted</a> by MCsaxmaster
For measuring the concentration of the solutions you could do a 50 or 100 fold dilution (or whatever dilution you'd like to) and measure the concentrations. Make sure you're as accurate as possible in diluting, otherwise your calculated values will be off.

A possible and perhaps likely reason that the you need to use more of the calcium solution is that the actual calcium concentration is lower than calculated value due to hydration of the calcium chloride. Calcium chloride picks up water very, very easily (used as a dehydrant in some applications because it sucks up water so easily). This means that you may have mixed up a more dilute solution than you intended because much of the mass/volume of the salt was actually just water.

That does seem like a lot of dosing, so I'd be suspicious that a lot of what you're adding is precipitating abiotically. How exactly are you adding these solutions?

cj

I'm using aquatronica dosing pump, suck from a 8gal storage bottle (seal) and dose directly into my sump at a very high flow area. I did monitor, it is like 1ml/30sec or a min. same happens to kh and ca with an hour apart

Potentially, I have made a mistake when mixing the solution. Anyway, will try your 100 fold dilution method since the suppose solution should be Ca - 47000ppm.

many thanks

[chercm]

guys who to increase mg ?

[Aquarist007]

<a href=showthread.php?s=&postid=11055054#post11055054 target=_blank>Originally posted</a> by chercm
guys who to increase mg ?

Do you mean how to increase mg.

Make sure you measure first---it should be at 1300.

I use Kent Tech-m

[chercm]

<a href=showthread.php?s=&postid=11055715#post11055715 target=_blank>Originally posted</a> by capn_hylinur
Do you mean how to increase mg.

Make sure you measure first---it should be at 1300.

I use Kent Tech-m

i tried using Kent Tech-M but i cannot get the 1300. does it help by using epsom salt ?

[JB NY]

I use ESV liquid mg

[Aquarist007]

<a href=showthread.php?s=&postid=11055852#post11055852 target=_blank>Originally posted</a> by chercm
i tried using Kent Tech-M but i cannot get the 1300. does it help by using epsom salt ?

what are your calcium and magnesium levels? and how are you dosing calcium?

[chercm]

i am using kent marine turbo calcium

[Aquarist007]

<a href=showthread.php?s=&postid=11060010#post11060010 target=_blank>Originally posted</a> by chercm
i am using kent marine turbo calcium

good product

its really important to know your calcium, magnesium , alk and pH levels---can you post these?

[Zedar]

Joyt,

why are you dosing so much so fast? 90ml every 2 hrs? thats too much.

I run my dosers 24/7

I dose 11 ml per hour of each.

11ml x 24 hrs = 264 ml per day

Its better to dose slowly all day long then large amount quickly.

I arrived at that value easily. I did a search on RC to find what most people were dosing for my tank size. I started with that figure (9ml per hr I think it was) and fine tuned it from there.

I recently went to dosing Kalk using a reactor to lower my 2 part usage and to raise my pH. Its working beautifully.
Between running a hose to the outside for the skimmer and running Kalk my pH has gone from 77 to 8.1

[Joyt]

<a href=showthread.php?s=&postid=11074180#post11074180 target=_blank>Originally posted</a> by Zedar
Joyt,

why are you dosing so much so fast? 90ml every 2 hrs? thats too much.

I run my dosers 24/7

I dose 11 ml per hour of each.

11ml x 24 hrs = 264 ml per day

Its better to dose slowly all day long then large amount quickly.

I arrived at that value easily. I did a search on RC to find what most people were dosing for my tank size. I started with that figure (9ml per hr I think it was) and fine tuned it from there.

I recently went to dosing Kalk using a reactor to lower my 2 part usage and to raise my pH. Its working beautifully.
Between running a hose to the outside for the skimmer and running Kalk my pH has gone from 77 to 8.1

Zedar,

Discover that my Ca solution was too diluted after using cj measuring method. dreaming while mixing the solution :). Now, everything is back to normal.:lol:

[ahchung]

May I know what is the difference you observed from SPS when magnesium level is at 1450-1500 ppm compared with that of 1300 ppm?

<a href=showthread.php?s=&postid=10500592#post10500592 target=_blank>Originally posted</a> by JB NY

Magnesium.
...
I personally like to maintain magnesium levels at 1450-1500 ppm. For me that has worked out best. it allows me to easily maintain my alk and ca levels and my corals seem to do best at this level as well.
...

[JB NY]

I felt I had less problems keeping alk and ca stable. Also I personally felt I had slightly better coloration, YMMV on that part.

[Aquarist007]

<a href=showthread.php?s=&postid=11201309#post11201309 target=_blank>Originally posted</a> by JB NY
I felt I had less problems keeping alk and ca stable. Also I personally felt I had slightly better coloration, YMMV on that part.

I think it was posted somewhere that high levels of magnesium carbonate can interfer with coral uptake of carbonates from calcium carbonate. I think it also went on that in very high levels of magnesium the corals can use it but with much less effeciency then they do with calcium carbonate.

[JB NY]

What is considered very high?

[Aquarist007]

<a href=showthread.php?s=&postid=11205099#post11205099 target=_blank>Originally posted</a> by JB NY
What is considered very high?

1500ppm or more

the articles/threads are on my laptop--I'll post them tomorrow

[MCsaxmaster]

<a href=showthread.php?s=&postid=11205565#post11205565 target=_blank>Originally posted</a> by capn_hylinur
1500ppm or more

the articles/threads are on my laptop--I'll post them tomorrow

Please do as I'm curious. Suffice it to say, things cannot be quite as you described above ;)

[Aquarist007]

<a href=showthread.php?s=&postid=11205621#post11205621 target=_blank>Originally posted</a> by MCsaxmaster
Please do as I'm curious. Suffice it to say, things cannot be quite as you described above ;)

lol--I think they were threads from you on magnesium-LOL

won't be the first time I interpreted wrong:o

[Aquarist007]

<a href=showthread.php?s=&postid=11205621#post11205621 target=_blank>Originally posted</a> by MCsaxmaster
Please do as I'm curious. Suffice it to say, things cannot be quite as you described above ;)

I checked back on this thread--on page six you wrote a great piece on magnesium---but this was not the thread.

I only have a modest background in chemistry, but usually I am not too far off on comprehending what I have read.

With your obvious fantastic expertise perhaps you can clarify "things not cannot be "quite as your described above"

I'll concede to "quite" as a very tactful way of remarking about this :o
and ask your help here in clarifying.

[cwegescheide]

One thing I notice is my PH is higher when my Alk is low.

[gary faulkner]

<a href=showthread.php?s=&postid=11467987#post11467987 target=_blank>Originally posted</a> by cwegescheide
One thing I notice is my PH is higher when my Alk is low.

I think that is a given, right?

[MCsaxmaster]

quote:
--------------------------------------------------------------------------------
Originally posted by cwegescheide
One thing I notice is my PH is higher when my Alk is low.
--------------------------------------------------------------------------------



I think that is a given, right?

No, with lower alkalinity the pH will be lower, all other things being equal. If pH here really is lower when the alkalinity is higher, then CO2 must covary with alkalinity in this case. Hence, the CO2 becomes significantly higher as alkalinity climbs higher, causing the reduced pH.

cj

[cwegescheide]

<a href=showthread.php?s=&postid=11469478#post11469478 target=_blank>Originally posted</a> by MCsaxmaster
No, with lower alkalinity the pH will be lower, all other things being equal. If pH here really is lower when the alkalinity is higher, then CO2 must covary with alkalinity in this case. Hence, the CO2 becomes significantly higher as alkalinity climbs higher, causing the reduced pH.

cj

Since my supplementation is provided by a calcium reactor I guess I buy that. My thinking was/is the amount of alkalinity supplied by my reactor is buffering my ph, not allowing it to rise above a certain point. EVERY time my ph goes above a certain point (just recalibrated my probe - it was reading 8.6 but I know its not that high) I know my Alk is low. Now I'm not sure if its because the amount of bicarbonate in suspension is low or its the lack of Co2 in the tank.. Since CJ is working on his MS in Marine Biology I will take his word for it ;)

[gary faulkner]

<a href=showthread.php?s=&postid=11469478#post11469478 target=_blank>Originally posted</a> by MCsaxmaster
No, with lower alkalinity the pH will be lower, all other things being equal. If pH here really is lower when the alkalinity is higher, then CO2 must covary with alkalinity in this case. Hence, the CO2 becomes significantly higher as alkalinity climbs higher, causing the reduced pH.

cj

Sorry, I read that wrong. If my Ph falls I always check to see if the alk is lower. It has a direct relationship not inverse?

Thanks

[Aquarist007]

<a href=showthread.php?s=&postid=11473453#post11473453 target=_blank>Originally posted</a> by gary faulkner
Sorry, I read that wrong. If my Ph falls I always check to see if the alk is lower. It has a direct relationship not inverse?

Thanks

that would be a direct relationship

[MCsaxmaster]

<a href=showthread.php?s=&postid=11473453#post11473453 target=_blank>Originally posted</a> by gary faulkner
Sorry, I read that wrong. If my Ph falls I always check to see if the alk is lower. It has a direct relationship not inverse?

Thanks

pH is positively correlated with total alkalinity and negatively correlated with total CO2. Raise total alkalinity, everything else equal, and you'll raise pH. Raise total CO2, everything else equal, and you'll lower pH. Raise both total alkalinity and total CO2 proportionally and you'll maintain the same pH.

These relationships ARE NOT linear, but understanding the general form of the relationships is very useful.

[morphlingman]

Great post people. Lots of advice.
One year ago a purchased a two chamber reactor (B-Ionic could not keep up with Calcium demands), filled with Arm media, it worked great for the first 6-8 months, but the past 4 months or so it has difficult. I find myself doing tests and adjustments every two or three days. Over the past 4 months results have been as follows. Alk jumps around 9-16, Calcium also up and down 340-410 and just tested Mg for the first time yesterday 1100 (starting to supplement).
Has anyone had problems with effluent flow going down daily. As an example I could set it at 30 ml/min and the next day sometimes sooner it has gone down to 28, even 26, ml/min. (Yes I have replaced the in & out tubes and cleaned (rinsed) adjustment valves.

[melev]

I would check to see if the feed pump to the reactor (from the sump) is unobstructed, as well as the physical connection where it goes into the Calcium Reactor. Mine clogs up with detritus and it is a pain to clean out.

To help keep your calcium reactor's output more consistent and avoid Alkalinity swings like you've posted, I would (and do) use a pH Controller. That way it will turn the CO2 on and off as necessary and your tank remains safer.

[MIKE NY]

x-2....I keep a PH probe in the effluent cup so I'll know right away if something is wrong......

[Reefun]

I’ve read this thread from the first page and didn’t see anything like my problem. Hope it’s ok to ask this here. I’ve never had a tank with a lot of sps and I plan on adding a lot more. So I’m doing my best to better understand the demands of a sps only tank. I’ve been in the hobby for a long time but this is a little different than my previous setups.
My ph is 8
Mg is 1380
Cal is 440
DKH is now 9-10 but just got it there
In about 100gal
My ph, Mg and calcium were and are stable but my alk would not stay up. I was adding about a teaspoon a day of Kent super buffer -dkh just to keep dkh from slipping below 8. After about two weeks of this I got a test kit for MG and it was and is at 1380. I don’t know how it got there because my freshly mixed salt is at 1100. I switched about a week ago to Kent coral builder and after using about 4oz my DKH is now around 9-10. I’ve ordered a bulk two part kit that should be in next week so I will not continue to use the Kent products at that point.
So basically my two questions are:
1. How could my dkh keep going down while calcium remained relatively unchanged?
2. How did my magnesium level get to where it is now? Nothing was ever added to the tank other than the Kent products mentioned and Kent turbo calcium in very small amounts.
Tank is just over two months old and only in the last month had anything in it that would use calcium

[MCsaxmaster]

<a href=showthread.php?s=&postid=12405563#post12405563 target=_blank>Originally posted</a> by Reefun
So basically my two questions are:
1. How could my dkh keep going down while calcium remained relatively unchanged?

The most likely answer, if the result were “real” (see what I mean below) would be the addition of an acid. An acid will reduce alkalinity without necessarily affecting calcium.

In order to measure a change in concentration of something in sea water (e.g., calcium concentration, magnesium concentration, total alkalinity) we have observe a change in concentration larger than the error of our analytical method.

For example, the accuracy with which we can measure calcium concentration in sea water is about +/- 5%, which really isn’t too bad for a hobbyist grade test kit. Since the calcium concentration in NSW is ~412 ppm we can measure the concentration accurately to within about +/- 20 ppm. In other words, if the calcium concentration changes by less than ~20 ppm, we cannot accurately or confidently measure a change in concentration. This also means that if we measure a concentration of 400 ppm, the real concentration should be within roughly the range of 380-420 ppm, but we cannot determine where it is in that range without using a more accurate analytical method.

For total alkalinity we see the same sorts of concerns. We can measure alk. to within a margin of error, but we can’t determine where in that margin of error the real value is—we can just shrink the error by using better methodology. For alk. measurements we can typically see an error of about +/- 1 dKH (or about +/- 0.35 meq/l). So, if we measure 9 dKH, the real value is likely somewhere in the range of 8-10 dKH. If the alk. changes more than 1 dKH we can measure a change in total alkalinity, but we cannot accurately measure a change if the change is not at least that large.

When calcium is removed from the water to build skeletons, two equivalents of alkalinity are also removed:

Ca2+ + 2HCO3- = CaCO3 + CO2

This reaction proceeds as a molar ratio, not as a mass ratio. We normally measure calcium based on mass (ppm calcium is equivalent to grams of calcium per kilogram of SW). If you do the calculation you find that for every 1 meq/l = 2.8 dKH of total alkalinity you remove from the water you also remove 20 ppm calcium.

Recall, we have to remove a MINIMUM of 20 ppm calcium just to be able to accurately measure any change at all. In order to achieve this change in calcium we have removed roughly 3x the amount of alkalinity we need to in order to see a change in concentration.

Imagine, for example, that you measure a drop in alk. of 1 dKH in your aquarium after a couple of days. That is a big enough change to say with confidence that the alk. has fallen by about 1 dKH. How much should the calcium have changed? The calculation is fairly simple: 20/2.8 ~ 7 ppm. That change in calcium is too small to measure, meaning that we would get about the same measured value for calcium. This could give us the impression that alkalinity is falling while calcium is remaining stable, however, this is an artifact that results simply due to the nature of measuring these parameters in SW. There is almost 5 times as much calcium in NSW as there is alkalinity. We can easily measure a 10% change in calcium concentration or total alkalinity in your sea water, but a 10% reduction of alkalinity causes less than a 2% change in calcium due to the difference in background concentration.

The most likely scenario is that both are decreasing, but due to the nature analytical chemistry and statistics, you can only measure that change that is occurring in both by measuring alkalinity.

<a href=showthread.php?s=&postid=12405563#post12405563 target=_blank>Originally posted</a> by Reefun
2. How did my magnesium level get to where it is now? Nothing was ever added to the tank other than the Kent products mentioned and Kent turbo calcium in very small amounts.
Tank is just over two months old and only in the last month had anything in it that would use calcium

No idea…more info please.

Chris

[Reefun]

Ok that answers my DKH question. I did add a small amount of calcium so It is very possible it moved less than my test could detect .
But the magnesium is still confusing me. I like the level it’s at but I want to know how it got there so I don’t raise it even higher. I ran the test for mg three times with a Red Sea test. The only thing I’ve read that suggest were the mg could have come from is the label of the Kent coral builder. It reads “Coral builder is designed to have only minimal impact on calcium, MAGNESIUM or strontium levels unlike other buffers.” So could it have come from the Kent super buffer-dkh?
There is really not much else to say about the tank I’ve not added any thing other than the mentioned products. If there is anything more you need to know please let me know.

[MCsaxmaster]

Hmmm, do you now or have you in the past used tapwater in the tank (as opposed to RO/DI)?

[Reefun]

Never used tap water all water came from my RO/DI and it has only made about 500gal. All filters are good.

[Reefun]

Could it have come from a bag of salt that was off?

[Aquarist007]

I am still trying to check out the coral builder as to what exactly is in it. I hate it when a company won't list the ingredients of a product.
The statement "minimal impact" on magnesium--that brings up a red flag for me :)
I'll ask on the reef chemistry forum

[Aquarist007]

here is the link to the thread in the chem forum

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1378557

[Reefun]

Thanks

[matan_grin]

nice post..:)
learnd a lot from it

[khoivo1]

i have the same problem ,,,now i am setting up calcium reactor,,,
how do i increase alk alone,,without raise cal ?? with geo cal reactor,,,
my alk going down very fast,,,but cal is going down slow,,,any one own calcium reactor please help me thanks


<a href=showthread.php?s=&postid=12405563#post12405563 target=_blank>Originally posted</a> by Reefun
I’ve read this thread from the first page and didn’t see anything like my problem. Hope it’s ok to ask this here. I’ve never had a tank with a lot of sps and I plan on adding a lot more. So I’m doing my best to better understand the demands of a sps only tank. I’ve been in the hobby for a long time but this is a little different than my previous setups.
My ph is 8
Mg is 1380
Cal is 440
DKH is now 9-10 but just got it there
In about 100gal
My ph, Mg and calcium were and are stable but my alk would not stay up. I was adding about a teaspoon a day of Kent super buffer -dkh just to keep dkh from slipping below 8. After about two weeks of this I got a test kit for MG and it was and is at 1380. I don’t know how it got there because my freshly mixed salt is at 1100. I switched about a week ago to Kent coral builder and after using about 4oz my DKH is now around 9-10. I’ve ordered a bulk two part kit that should be in next week so I will not continue to use the Kent products at that point.
So basically my two questions are:
1. How could my dkh keep going down while calcium remained relatively unchanged?
2. How did my magnesium level get to where it is now? Nothing was ever added to the tank other than the Kent products mentioned and Kent turbo calcium in very small amounts.
Tank is just over two months old and only in the last month had anything in it that would use calcium

[MCsaxmaster]

<a href=showthread.php?s=&postid=12539950#post12539950 target=_blank>Originally posted</a> by khoivo1
i have the same problem ,,,now i am setting up calcium reactor,,,
how do i increase alk alone,,without raise cal ?? with geo cal reactor,,,
my alk going down very fast,,,but cal is going down slow,,,any one own calcium reactor please help me thanks

Calcium will always appear to get used slower than alkalinity. This is an apparent result stemming from the fact that there is ~5x as much calcium in sea water as alkalinity and to produce calcium carbonate it takes 1 equivalent of calcium but 2 equivalents of carbonate alkalinity.

A calcium reactor will return calcium and alkalinity in very close to the same ratio that they are used (1:2) since you are simply dissolving CaCO3 (though in reality there is some MgCO3, a small amount of SrCO3 and several impurities layed down by calcifiers in the tank and present in the reactor media). Since there is a large background concentration of calcium in the water, it takes a heck of a lot of calcification to notice a change in concentration. On the other hand, since there is a far smaller background concentration of carbonate alkalinity it doesn't take as much calcification to be able to notice the alkalinity dropping. The important thing to understand is that we have the *appearance* of different rates of change not because calcium and alkalinity are being sucked out at an imbalanced rate, but simply because of an artifact of measurment.

Thus, probably all you need to do is adjust your reactor a bit higher. That will raise both calcium and alkalinity properly. However, since there's already a lot of calcium, it will be a proportionally small change. Since there is much less alkalinity, it will be a proportionally large change.

In terms of the actual stoichiometry: if you dissolve 1 milliequivalent of CaCO3 in a liter of water you'll raise the alkalinity 1 meq/l and you'll raise the calcium ~20 ppm.

Chris

[Aquarist007]

IMO it is not said enough-- MCsaxmaster--thank you for all the detailed posts you make, I and I am sure others have learned alot from you. :)

[MCsaxmaster]

I aim to please :thumbsup:

[khoivo1]

thanks alot,,i learned some thing today ,,,
any way what is acceptible range of
ALK?? 7.0dkh-11dkh??
CAl?? 360--450???
mag?? 1260-1400???
is that right?? thanks

[MCsaxmaster]

Yeah, that's probably not bad. For magnesium I'd shoot for right around NSW levels: 1250-1350 ppm seems appropriate (NSW ~1285 ppm). There's no reason to think higher magnesium is actually doing anything good, while low magnesium can cause excessive abiotic CaCO3 precipitation problems.

For calcium I'd shoot for at or perhaps just slightly higher than NSW: 400-450 ppm seems appropriate (NSW ~ 412 ppm). There's very little reason to think that calcium higher than that actually encourages faster calcification in most corals. Below 400 ppm, however, you may start running into calcium limitation of calcification, but calcification is only reduced slowly from ~400 down to maybe ~300 ppm. From 300 to 200 ppm calcifcation drops off much faster. Below 200 ppm calcification drops like a rock.

I'd maintain a minimum of 7 dKH total alkalinity (assuming normal borate levels). NSW has ~6.6 dKH total alk. Critters do just fine in that, but most certainly calcify faster with higher alk. I've generally had the best success maintaining TA in the neighborhood of 9-12 dKH.

Oh, and the NSW parameters all assume standard sea water (35 ppt, 25 C, 1 atm, etc.).

Chris

[Marshall Haith]

I don't think this issue has been discussed.

Problem: annoying buildup of what looks like calcium precipitate on glass (white chalky stuff that is hard to scrape off), mainly, but not exclusively, on sides where the flow from the power heads is directed and on front middle glass where the flow from the two heads meets.

Parameters:
50 g tank, 5 g sump
ph around 8.0
calc around 325
dkh around 6.5 to 7.0
mag at around 1280-1300
water changes of 8% or so/week
light coral load

Trying to raise calc to around 425 without much luck. I'm using 2-part solution, adding 100 ml of calc/day and 100 ml of buffer. These are added in 50 ml doses. each in about a half liter of water, to sump through a gravity drip at around 2 drips/sec.

The values are around 2.5X what I think Randy suggests for this size and type of tank, but the calcium level isn't changing much (after about 2 gals of mix have been added over several weeks). The precipitate is terribly annoying and time consuming to remove and suggests that I may be adding too much. I've checked the calk, ph and dkh measures against store measures and my son's kits.

The heater glass did have a substantial buildup, but I cleaned it two weeks ago, and it doesn't seem to be accumulating a film very quickly. I haven't checked the pumps internally, but they don't look bad at all on the outside.

Befuddled.

[MCsaxmaster]

Huh--could you post a picture? Accumulating preferentially in areas of strong flow sems strange.

cj

[Aquarist007]

<a href=showthread.php?s=&postid=10531583#post10531583 target=_blank>Originally posted</a> by Sk8r
Bertoni came up with an interesting observation: if you are supplementing [an dI hope I'm quoting him right] with 2-part or Kent's or whatever, you're actually adding some mg.

If you are supplementing with kalk, you are not, because there is no mg in kalk.

So if the corals are using mg, and you are not supplying it via your supplement, the net effect is that you are losing mg and need to supplement more.

That may reconcile Randy with Bertoni. Bertoni makes those comments in the thread I linked to above.

I agree with your statements.
Corals actually don't use that much magnesium--regular water changes with the appropriate salt mix can help keep the mag up

Look at the differences in levels in the different mixes that Billybeau has put together

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1287118

[Marshall Haith]

Huh--could you post a picture? Accumulating preferentially in areas of strong flow seems strange.

c j

Thanks Chris. Posted are a couple of photos, the closeup being of the center front glass. You are right. The calc buildup is actually to the side of the powerheads and below them, not in the output stream, so the water is pretty slow-moving there. In front, the output streams from the two powerheads meet, so they cancel one another, and the flow is pretty slow there also.

mhhttp://reefcentral.com/gallery/data/500/189293calcium_1a.jpg http://reefcentral.com/gallery/data/500/189293calcium_2a.jpg

[Aquarist007]

<a href=showthread.php?s=&postid=12772714#post12772714 target=_blank>Originally posted</a> by Marshall Haith
Huh--could you post a picture? Accumulating preferentially in areas of strong flow seems strange.

c j

Thanks Chris. Posted are a couple of photos, the closeup being of the center front glass. You are right. The calc buildup is actually to the side of the powerheads and below them, not in the output stream, so the water is pretty slow-moving there. In front, the output streams from the two powerheads meet, so they cancel one another, and the flow is pretty slow there also.

mhhttp://reefcentral.com/gallery/data/500/189293calcium_1a.jpg http://reefcentral.com/gallery/data/500/189293calcium_2a.jpg

<img src="/images/welcome.gif" width="500" height="62"><br><b><i><big><big>To Reef Central</b></i></big></big>

could you possible take out an album on www.photobucket.com
you upload your pictures to your album
under each pic is four codes
you use the fourth code----the "img" code to copy and paste into your posts

You get a much bigger and clearer picture when doing that then using the gallery here.

[Marshall Haith]

could you possible take out an album on www.photobucket.com


Ok, here they are.

mh

http://i278.photobucket.com/albums/kk105/mhaithatdu/calcium1.jpg

http://i278.photobucket.com/albums/kk105/mhaithatdu/calcium2.jpg

[Aquarist007]

<a href=showthread.php?s=&postid=10521969#post10521969 target=_blank>Originally posted</a> by Sara B
I do use a Salifert Magnesium test kit. I also run a Kalk reactor on both systems and drip with top-off water 24/7. The reactors stir the Kalk 4 times a day for 15 minutes at a time. I have a basement fishroom and my PH remains in the range of 7.8 to 8.0 as the A/C running all summer has an effect on it's level. In the fall and winter its more in the 8.2 range as I have a vent that's open for fresh air in the room.

had the same problem last summer. I keep a window open in the basement 24/7. That kept not following below 8.0.This spring I added a second 37 gal fuge--that keeps the pH at 8.19
If you can't keep the window open vent the skimmer to the outside--that will make a difference

[Aquarist007]

<a href=showthread.php?s=&postid=12774694#post12774694 target=_blank>Originally posted</a> by Marshall Haith
Ok, here they are.

mh

http://i278.photobucket.com/albums/kk105/mhaithatdu/calcium1.jpg

http://i278.photobucket.com/albums/kk105/mhaithatdu/calcium2.jpg

much better;)

I would assume your low dkH values are behind the precipitation
You should be running 10-11.5 dkH

[Marshall Haith]

I would assume your low dkH values are behind the precipitation

Hmm. I was using this article by Randy Holmes-Farley as a guide: http://reefkeeping.com/issues/2005-07/rhf/index.php. The article indicates that increasing alk exacerbates the problem of calc precipitation, so I was shooting for the lower end of the operating range for alk.

mh

[JB NY]

I agree, I've never had ca precipitation with low alk, only high.

[fishdoc11]

Me too, only high:)

FWIW in the pics above it looks a bit more like some sort of coraline (or something else) than Ca precipitation.

Chris

[Aquarist007]

but at what levels did you get the precipitation?

IMO keeping the alk between 8-11 is better then keeping it in the low 7's?
I am sure Randy mentioned something about low alkalinity

[Marshall Haith]

Actually, I've had the dkh in the 8-10 range, and I had the same problem.

mh

[MCsaxmaster]

Marshall,

How are you measuring pH?

I would assume your low dkH values are behind the precipitation

Huh-uh. All else equal (e.g., pH, temperature, precense of nucleation sites, etc.), with lower carbonate alkalinity you'll have lower rates of CaCO3 precipitation.

The rate of precipitation depends mostly on saturation state (assuming there are available nucleation sites, which is probably a good assumption in an aquarium full of pieces of CaCO3 rock/sand ;) ). Saturation state, at a given temperature, salinity, pressure, is described by:

omega = [Ca++][CO3=]/Ksp*

where [Ca++] is the calcium concentation, [CO3=] is the carbonate concetration, and Ksp* is the solubility product (adjusted for use in sea water). If calcium goes up, satuation state goes up proportionally. If carbonate goes up, saturation state goes up proportionally. Carbonate concentration is controlled by carbonate alkalinity and pH (all else equal). The higher the alkalinity, all else equal, the more carbonate there is. The higher the pH, all else equal, the more carbonate there is. If both alkalinity and pH go up, carbonate goes up more still. You get the idea.

[Aquarist007]

<a href=showthread.php?s=&postid=12781414#post12781414 target=_blank>Originally posted</a> by MCsaxmaster
Marshall,

How are you measuring pH?

I would assume your low dkH values are behind the precipitation

Huh-uh. All else equal (e.g., pH, temperature, precense of nucleation sites, etc.), with lower carbonate alkalinity you'll have lower rates of CaCO3 precipitation.

The rate of precipitation depends mostly on saturation state (assuming there are available nucleation sites, which is probably a good assumption in an aquarium full of pieces of CaCO3 rock/sand ;) ). Saturation state, at a given temperature, salinity, pressure, is described by:

omega = [Ca++][CO3=]/Ksp*

where [Ca++] is the calcium concentation, [CO3=] is the carbonate concetration, and Ksp* is the solubility product (adjusted for use in sea water). If calcium goes up, satuation state goes up proportionally. If carbonate goes up, saturation state goes up proportionally. Carbonate concentration is controlled by carbonate alkalinity and pH (all else equal). The higher the alkalinity, all else equal, the more carbonate there is. The higher the pH, all else equal, the more carbonate there is. If both alkalinity and pH go up, carbonate goes up more still. You get the idea.

gottcha---thanks very much for the detailed answer:smokin:

[gary faulkner]

<a href=showthread.php?s=&postid=12781508#post12781508 target=_blank>Originally posted</a> by capn_hylinur
gottcha---thanks very much for the detailed answer:smokin:


Capn,

Sounds Greek to me too.:D

[MCsaxmaster]

Greek, geek, whatever ;)

[fishdoc11]

Geek here:D

[Aquarist007]

<a href=showthread.php?s=&postid=12788420#post12788420 target=_blank>Originally posted</a> by gary faulkner
Capn,

Sounds Greek to me too.:D

I wasn't kidding---I did follow the drift--Mcsaxmaster does explain chemistry well:smokin:

[Zedar]

<a href=showthread.php?s=&postid=12542684#post12542684 target=_blank>Originally posted</a> by MCsaxmaster


I'd maintain a minimum of 7 dKH total alkalinity (assuming normal borate levels). NSW has ~6.6 dKH total alk. Critters do just fine in that, but most certainly calcify faster with higher alk. I've generally had the best success maintaining TA in the neighborhood of 9-12 dKH.

Oh, and the NSW parameters all assume standard sea water (35 ppt, 25 C, 1 atm, etc.).

Chris

What is your opinion on ULNS? People that maintain ULNS through carbon dosing have experienced basal STN when running their systems above 8 dkh.

I myself run one of these systems and have experienced this first hand.

[MCsaxmaster]

ULNS?

[Zedar]

ultra low nutrient systems

people that dose a carbon source can take P04 and N03 down to these levels.

At these levels raising alk above NSW has caused basaL stn

[Zedar]

dbl post

[Zedar]

triple post :)

[MCsaxmaster]

<a href=showthread.php?s=&postid=13074331#post13074331 target=_blank>Originally posted</a> by Zedar
ultra low nutrient systems

people that dose a carbon source can take P04 and N03 down to these levels.

At these levels raising alk above NSW has caused basaL stn

I've heard complaints of recession when alkalinity is higher than ~8 dKH from people using zeovit systems, but I'm not sure I've heard of it elsewhere. I've heard of this phenomenon from enough people to suspect something is going on, but it's not clear what. I don't see any reason to expect a reaction like that when alkalinity is elevated to that level. If you raise alkalinity in NSW (e.g., w/NaHCO3), corals grow faster, and they don't experience recession. Lots and lots of people, myself included, have maintained higher alkalinity in captivity for years with good success. If there really is a problem associated with higher alkalinity there, it strikes me as a problem with the system, but an unusual one to be sure.

Also, I'm not sure that a term like "ultra low nutrient system" is apt for systems that doses organic C sources. Some of these systems may indeed achieve low dissolved inorganic N and P in the water column, but that can be achieved with other systems as well. Also, simply because organic C is dosed, or zeolites are used, or whatever else and the intention is to have very low DIN and DIP does not mean that one actually achieves such conditions. Without some good nutrient measurements, one really cannot say what nutrient levels are like at the low end of things, except to say lower than the detection limit on their test kits. The water overlying a typical coral reef will pretty much always have undetectable nutrient levels though. But, to be fair the corals are not actually in contact with that water--they are in contact with water in several boundary layers overlying the reef, where dissolved nutrients can be up to several orders of magnitude higher than in the overlying water. Corals also tend to eat a lot of zooplankton/pseudoplankton in nature, so they have access to a lot more in the way of N and P than we might often appreciate.

Chris

[tyreeftank]

I have 75g tank:
Calcium = 160 ppm
magnesium = 900 ppm
alk = 12 dkh
ph=8.2.

I need to increase my calcium and magnesium. Do I increase my magnesium first then calcium? I manage to increase my magnesium to 1000 ppm now. Should I start adding calcium as I adding magnesium?

[melev]

You can definitely start adding more calcium to the water, assuming that test result is correct. It seems quite low. Which tank is this test for? The 150g or the 75g? A big healthy water change should help bring that up to normal levels, usually (depending on the brand of salt you use).

You might have your LFS (local fish store) test your water to compare their results to yours.

[tyreeftank]

<a href=showthread.php?s=&postid=13282926#post13282926 target=_blank>Originally posted</a> by melev
You can definitely start adding more calcium to the water, assuming that test result is correct. It seems quite low. Which tank is this test for? The 150g or the 75g? A big healthy water change should help bring that up to normal levels, usually (depending on the brand of salt you use).

You might have your LFS (local fish store) test your water to compare their results to yours.


This is for my 75g tanks. My LFS test my Mg and Calcium for me, since I dont have Mg test kit. I compare the Calcium result from my LFS with my test kit and it match. I dont know with it soo low. I was told that since my Mg is so low, I will not be able to increase my Cal until my Mg is at a reasonable level. I will try to add calcium and see if it change. Thanks for the advise.

[melev]

It is true that they work together. Raising the Mg will help. The target range is in a few of Randy's articles.

Cal - 370 to 425
Alk - 8 to 11 dKH
Mg 1300 or more (my preference)

Mg should be 3x the calcium reading. So it shouln't be tough to bring it up to 300ppm at least, pretty much double what you have now. I just think the reading is false, unless...

If you are dosing calcium, don't just dump it in. Pour it in very gradually into an area of strong flow so it doesn't turn to a solid. You don't want to see snowflakes in the water.
If you are making your own saltwater, add the salt to a barrel of water. Do NOT put the salt in the bucket first, then add the water as it will precipitate out. This is discussed in this article briefly:

http://reefkeeping.com/issues/2007-11/nftt/index.php

[tyreeftank]

Well after some water change, dosing with Kent Turob Calcium, Kent Tech-M, and 2.5 lb of Epsom Salt, my water parameters are as follow:

Cal - 400
Alk - 10 dkH
Mg - Not test yet. From my estimate values from dosing with Tech-M and Epsom Salt. It probably 1400. Hopefully it stay this way. I also start running my Kalk Reactor as my auto top off.


<a href=showthread.php?s=&postid=13287013#post13287013 target=_blank>Originally posted</a> by melev
It is true that they work together. Raising the Mg will help. The target range is in a few of Randy's articles.

Cal - 370 to 425
Alk - 8 to 11 dKH
Mg 1300 or more (my preference)

Mg should be 3x the calcium reading. So it shouln't be tough to bring it up to 300ppm at least, pretty much double what you have now. I just think the reading is false, unless...

If you are dosing calcium, don't just dump it in. Pour it in very gradually into an area of strong flow so it doesn't turn to a solid. You don't want to see snowflakes in the water.
If you are making your own saltwater, add the salt to a barrel of water. Do NOT put the salt in the bucket first, then add the water as it will precipitate out. This is discussed in this article briefly:

http://reefkeeping.com/issues/2007-11/nftt/index.php

[melev]

You really do need to test the Magnesium, just to maintain ionic balance in the tank. Glad to see your numbers are coming into line.

[Bonebrake]

What is your specific gravity or salinity?

That is the most likely reason your magnesium and calcium is so low. It is probably 26 ppt or 1.017 s.g. or something close to that.

[Torpus]

I just started added Mg to my 40g tank. I'm only adding 1tsp every third day instead of the perscribed 2tsps twice a week per 20g as recommended on the container because testing showed decent mg levels of 1200-1300 and I wanted to slowly raise it up to around 1400-1500.

My question is, has anyone had any bleeching as a result of starting to use Mg? I have one plating monti that started slowly bleeching right about when I started using Mg. There is no scientific evidence to show that the Mg is what is causing the bleeching in my tank besides timing, but the coral was doing really well until around the time I started adding the Mg.

[Aquarist007]

<a href=showthread.php?s=&postid=13629518#post13629518 target=_blank>Originally posted</a> by Torpus
I just started added Mg to my 40g tank. I'm only adding 1tsp every third day instead of the perscribed 2tsps twice a week per 20g as recommended on the container because testing showed decent mg levels of 1200-1300 and I wanted to slowly raise it up to around 1400-1500.

My question is, has anyone had any bleeching as a result of starting to use Mg? I have one plating monti that started slowly bleeching right about when I started using Mg. There is no scientific evidence to show that the Mg is what is causing the bleeching in my tank besides timing, but the coral was doing really well until around the time I started adding the Mg.

why are you bringing the mag level up to 1400-1500--it really only needs to be around 1300ppm
Are you adding the mag directly to the sump or display tank--I would try mixing it first in a separate container and then adding it to the tank.

[melev]

In my case, Magnesium makes my corals color up. Are you mixing the Mg in a cup of RO/DI water prior to pour it into the tank?

1400ppm works best with my system, but the general rule is 3x the calcium level of your tank. 1300ppm is the target for most people.

[Aquarist007]

<a href=showthread.php?s=&postid=13629739#post13629739 target=_blank>Originally posted</a> by melev
In my case, Magnesium makes my corals color up. Are you mixing the Mg in a cup of RO/DI water prior to pour it into the tank?

1400ppm works best with my system, but the general rule is 3x the calcium level of your tank. 1300ppm is the target for most people.

thanks for the tip:cool:

[melev]

You and I were posting at the same time, it seems. :)

[Torpus]

i do not mix the mag first, i just very slowly sprinkle the salt into a place where a pump sucks up the salt and blows it into the tank

[melev]

Definitely premix any powdered additives. You are probably stinging various corals in your system with the method you've described.

[jon56048]

Melev - YGPM

[Son Nhon]

You really hit this subject right on the spot. It is very important to keep these minerals stable in an SPS tank. I think STABILITY in general, keeps SPS healthy and happy.

[tatoofr]

Hello,
The make up water is at 12.5 dkh, and I keep my reef at 8 dkh,
How do I lower the alk in the make up water?
Thanks,
Frank

[M.A.F.]

does anyone know anything about the magnesium in Instant Ocean? i have been using it for about the last year and haven/tn had any loss, parameters seem to be good but i don't test for mag ever. I supplement with kalwasser and various coralvite, and phytoplankton as wek=ll as purple up during monthlys.
I only ask because I set up a new 150 for sps, still have lots of lps and mush, leathers but a superman monti is the only sps i have i think, Superman Montipora ? Encrusting
I'd appreciate the feed back?

[M.A.F.]

hey Frank, use RO/DI it removes the hardness and metals in water.

[Aquarist007]

<a href=showthread.php?s=&postid=13790678#post13790678 target=_blank>Originally posted</a> by tatoofr
Hello,
The make up water is at 12.5 dkh, and I keep my reef at 8 dkh,
How do I lower the alk in the make up water?
Thanks,
Frank

where are you getting your makeup water from?

[Aquarist007]

<a href=showthread.php?s=&postid=13798705#post13798705 target=_blank>Originally posted</a> by M.A.F.
does anyone know anything about the magnesium in Instant Ocean? i have been using it for about the last year and haven/tn had any loss, parameters seem to be good but i don't test for mag ever. I supplement with kalwasser and various coralvite, and phytoplankton as wek=ll as purple up during monthlys.
I only ask because I set up a new 150 for sps, still have lots of lps and mush, leathers but a superman monti is the only sps i have i think, Superman Montipora ? Encrusting
I'd appreciate the feed back?

you can check it out here:

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1287118

[Aquarist007]

<a href=showthread.php?s=&postid=13630021#post13630021 target=_blank>Originally posted</a> by melev
Definitely premix any powdered additives. You are probably stinging various corals in your system with the method you've described.

I like the new avitar Marc:cool: