I use ro Di water

The alkalinity of your RO/DI water may not be accurate, since you are probably using a saltwater test kit.

Or was that measurement of 12.5 dKH from the saltwater you just mixed? How long did you allow it to mix? I would wait 24 hours, allowing it to completely mix with a powerhead during that period. You could also add an airstone to oxygenate the water. Let us know what that number ends up being.

You need to measure the Magnesium with a test kit. Salifert or Elos both make one that is relatively easy to use. The numbers vary from bag to bag and bucket to bucket, so no matter what number you see published on this forum or any other, that doesn't mean every batch you mix will match it.

Randy Holmes Farley wrote several good articles on Magnesium. You can read how it works in our systems, as well as how to make your own Magnesium additive to dose the system.

http://reefkeeping.com/issues/2006-07/rhf/index.php

Jdieck made a Chemistry Calculator to determine how much you need to dose, which is very useful and something I use often.

http://reef.diesyst.com/flashcalc/flashcalc.html

HI Melve,
I did what you said and waited 24 hours and the alk is down to 9dkh, thanks,
Frank

Since you are changing a portion of your water, the slightly higher dKH will not affect the system adversely.

It is good to always check the pH of your aged (24 hours) saltwater, as it is an indicator of the alkalinity level. I discuss this near the end of this article:

How to Change Water in Your Reef Aquarium
http://reefkeeping.com/issues/2007-11/nftt/index.php

My Mg has been sky high, 1600+ since I started my tank 6 months ago. I have never dosed it once. My ca and alk are pretty easy to maintain (uptaking the same amount of a 2 part additive daily) but I would still like to maybe get it down to target levels.
I was using Instant ocean salt but now Tropic Marin Pro.
Any ideas what the heck its problem is?

What test kit are you using?

I have used a salifert and a Red Sea Max.

High magnesium is rarely an issue, so even if that number is true, don't worry about it. The only thing I know that seems affected by high Mg readings are snails. Some people dose it on purpose to kill back Bryopsis, a type of turf algae that looks like green hair algae. When they do, they dose even higher.

I would expect as your tank is more heavily stocked, that number will begin to deplete.

Btw, whenever you have an usual number, it is best to do the test three times in a row and then take the average of the three.

My tank is jam packed with corals as well as bryopsis haha. I haven't elevated my Mg levels at all because they are already so high. One day I did take a syringe and tried to shoot a little section. It didn't work. I recently got some lettuce nudis and found that my astrae snails like it. I am also working out some other small flaws with my system that may be contributing to the excess algae.

Here is a link to the byopsis thread--you might find some help there.
http://reefcentral.com/forums/showth...readid=1113109

I didn't scroll through it all but are you specifically pointing to the magnesium part? I have tried many different solutions including the MG with no luck.
However, as I stated above I heard that astrae snails might like it. 2 nights ago I took 3 astrae snails and put them on the bad area and 2 of them haven't moved since. They definitely have eaten some.
Also, now my bryopsis has become covered with the bubbly red slime algae and I think it is starting to kill it. I did a small water change today and sucked up a good amount of bryopsis. Normally I can't syphon the bryopsis but today it was pretty easy. I am thinking the other algae is weakening it.

IMO if you have tried all the methods suggested then a last option might be to take each rock out of the tank one by one and scrub them.

I may have to.....it's going to be such a pain though with all the corals on the rocks.

i think i have been posting my alk problem in the wrong thread but i decided to post it in this forum too to see if you guys can help me.

before my alk was 15
i decided to do a water change and now my alk is 16-17
tap water alk is 6-7
saltwater mix(reefcrystals) 11

how did my alk rise more?
how do i lower it?
ph is 8.2, i just rechecked it.

When you dose a buffer to raise pH like you stated in your other thread, that will raise the alkalinity of the reef as well.

You need to stop dosing for pH for the time being, and get your Alkalinity, Calcium and Magnesium levels where they belong. Also, salinity matters as it will affect how these numbers test out.

Salinity for a reef tank - 1.026 sg
Alkalinity - 8 to 11 dKH
Calcium - 370 to 450ppm
Magnesium - three times the calcium level (1300 - 1400ppm is what I shoot for)

oh i didnt know ph buffer brings up alk. no wonder why its up because i been trying to keep the ph at 8.2-8.4
now it all makes sense
so i will stop the ph buffer but what if my tanks ph goes down to 7.8 which is where its at without the buffer
but then again my new saltwater mix (reef crystals) ph is at 8.2

can you also explain to me a little bit about how salinity affects parameters. i have my salinity between the required levels on my salinity meter.

Don't worry about the pH, period. While it is a nice indicator, if you don't own a digital pH meter, there's no point even considering it. pH changes from minute to minute, and hour to hour. It is at its lowest early in the morning, and at its highest near the end of your peak lighting period.

Dosing various products can raise or drop pH in the tank. Kalkwasser and buffer brings it up, vinegar brings it down... just a few examples. Excess CO2 in the house brings it down, and fresh air brings it up.

The average pH we look for is 7.9 to 8.3, but there are many beautiful tanks that peak at 7.9 due to atmospheric conditions in their sealed up homes. Again, this is just a way to gauge the health of the tank and should not be the magic number you must attain.

The more salty the water is, the more your test results will be affected. If you test Magnesium with a salinity of 1.021 and then again with 1.026, you should see a difference. It may not be a big difference, but it shouldn't be the same reading.

What level do you keep your tank at? Between the required levels is a bit vague. Also, how you read a hydrometer is important if that is what you are using. Are you measuring how it hits the scale, or are you measuring it where it curls up the glass (due to water surface tension)?

i am really trying to keep my tank stable and from all this unstableness due to parameters going out wack due to me dosing i realize the best thing to do is keep it simple and learn patience.
so im really not gonna dose anything except for CA when i need it which is prob long from now because i only have a few sps's, iodine like once every 2 weeks for soft corals, and strominium for the sps's like once every 2 weeks too.
no more essential elements or buffers.
i realize my salt actually has good parameters.
i just did another water change today and hopefully with the saltwater mix alk at 11, it will lower my current alk of 16-17 to something lower.

i will try to keep my tank at 78 degrees, 400-450 cal, 10-12 alk, nitrate phosphate to zeros.
these are all the tests i have.

for salinity i guess i use the curl plastic thing tha tyou mentioned with has the correct parameters in the middle of it highlighted in red.

That sounds like a good plan. I really do recommend you get The Reef Aquarium Vol 3, which is on sale at Amazon.com for $54 currently. I think you'll get free shipping with that order, and it will be an excellent book for you to learn from. Give your reef a gift this holiday season, and it will make your hobby far more enjoyable because you'll understand much more about how this works, as well as many many other yet related topics.

I recommend Vol 3 to everyone new to the hobby. As well as my website, when you are done surfing Reef Central. ;)

Hi,for alkalinity and Ca I have been using B-ionic and my levels are as follows the alk at 13-14,Ca at 360 and steadily increasing. My PH at 8.4 and above. I also doze with kalkwasser with RO water which I picked up from youtube DIY projects which is in a one gallon container,one drip per two seconds. The testing equipment and pretty accurate are the salifert series,I also doze magnesium once a week because it keeps the Ca at safe level for corals to grow better and the coralline algae has taken off together with the corals and fish of course are healthier. Keeping alk at 14 keeps the doctors away as they say. Hope this helps
:)

You are running your alkalinity much too high. I don't know where you got the recommendation, but 8 to 11 dKH is a better target range usually.

If you use B-Ionic, it seems you wouldn't need to use any kalkwasser. Normally, that is the either / or discussion, with kalkwasser being the less expensive route.

my sps tank has been thriving with levels of 440 calcium, 1500 mag, alk 9, sal 1.25, with chido in the fuge to help keep nitrates to a minimum. i believe that the salt im using D-D H2Ocean Magnesium Pro PLUS Salt Mix has been the real key. the salt is awesome!! anyone else using this stuff

i no this might be little off track......my first post by the way but when i got my acros they turned browny coloured is this because of trace elements? as i was told to only have ca mg alk n ph in tact?

Marc,

Let me pick your brain just a bit, if I may :D

I absolutely agree that 8-11 dKH is an often recommended target and that higher than ~12 dKH is often said to be "too high" by many aquarists. I'm curious if you have thoughts on how it is or why it is a large part of the aquarist community has picked 11/12 dKH as a sort of threshold above which we prefer not tread?

As I said, I hear this very, very often, but I can think of absolutely no basis to use this particular value as any sort of threshold...besides that is what we hear and repeat so often :)

Chris

The general rule is to only dose what you can test for.

You have the right idea about the key ingredients. These are what I watch:

pH (just a glance to see that it is within target range of 8.0 and up)
Alkalinity
Calcium
Magnesium
Salinity (re-calibrate any measuring device to make sure it is accurate)
temperature (stability is key, I try to avoid more than a 2 degree fluctuation)
Nitrate should be as low as possible (under 10ppm)
Phosphate should be as low as possible (.03ppm or less)