PDA

View Full Version : 2 part dosing pump


jim5280
05/26/2009, 08:58 PM
So I'm planning to get a dosing pumps for 2 part solution. The pump is more for stability than conveinece. It seems that SPS are much more sensitive to ALK swings versus calcium. My calcium has been rock steady at 450 for months, but I bet my ALK swings with daily supplementation. Could I use just one pump for ALK supplementation and still dose calcium once daily in AM?
Thanks, Jim.

spleify
05/26/2009, 09:15 PM
Jim IMO if you are going to get a doser I think you would be happier if you just went with the dual.
I am actually curious about this aswell. I did just pick up a Aquamedic Dual dosing pumo that a buddy was not using any more so I am gonna give it a test and see how it works. I would like to hear what folks think about these units.

I have also heard really good things about the Drews dosers from BRS

graveyardworm
05/26/2009, 09:47 PM
I junked two Aquamedic pumps in just over 2 months each. I'll never buy one again. The metal shaft that holds the wheels in the plastic wears into the carrier, and it doesnt take much to lose enough pressure on the hose so it doesnt work. These were well lubricated. I was using them for top off though so they ran more than dosing and for longer periods. Your mileage may vary.

cham
05/27/2009, 04:59 AM
I've used aquamedic dosing pumps on all of my tanks for the past 3 years. I love them and never had a problem.

Logzor
05/27/2009, 06:37 AM
Litermeter III will do over 100 separate doses over a 24 hour period. You can not get much more stable than that. I use this for dosing alk/calcium and I love it.

polysynth
05/27/2009, 08:31 AM
Aquamedic Twin has been running my 2 part. Been very happy with it.

cham
05/27/2009, 08:44 AM
<a href=showthread.php?s=&postid=15083706#post15083706 target=_blank>Originally posted</a> by Logzor
Litermeter III will do over 100 separate doses over a 24 hour period. You can not get much more stable than that. I use this for dosing alk/calcium and I love it.


Aquamedic can be programed for up to 1,440 seperate doses per 24 hours.

You set how often to cycle the dose. Every two hours, every hour, every 30 minutes, every minute. Then you set how many seconds to run during that cycle. With 1,440 minutes in each day thats a lot of cycle options.

Nanook
05/27/2009, 08:48 AM
[moved]

kuyatwo
05/27/2009, 10:53 AM
i use a profilux dosing pumps with great results way better results then when i had my ca reactor setup

jim5280
05/27/2009, 01:15 PM
I'm sorry I guess my post was not clear. The question I'm trying to ask is can I dose ALK only with a dosing pump and manually dose calcium in an SPS tank?

Elan L.
05/27/2009, 01:57 PM
yea, i dont see why not?

kraziezx
05/27/2009, 02:20 PM
where and what type of calcium and alk do you guys use? is it more cost effective than calcium reactor?

polysynth
05/27/2009, 02:29 PM
I suppose you can dose separately but why? You have to gauge to make sure you're dosing the two part in equal parts, which i think may take a while to hone in. It's much easier to deal with alk and calc level when they're in line with each other than to have one much higher that the other.

How I see it is that if you're going to automate it, automate the whole process for consistency and convenience. What if you have be away for a weekend or something?

Just some things for you to consider...but all in all, you can do whatevers that work for you.

divewsharks
05/27/2009, 05:49 PM
<a href=showthread.php?s=&postid=15086191#post15086191 target=_blank>Originally posted</a> by polysynth
I suppose you can dose separately but why? You have to gauge to make sure you're dosing the two part in equal parts, which i think may take a while to hone in. It's much easier to deal with alk and calc level when they're in line with each other than to have one much higher that the other.

How I see it is that if you're going to automate it, automate the whole process for consistency and convenience. What if you have be away for a weekend or something?

Just some things for you to consider...but all in all, you can do whatevers that work for you.

you don't have to dose equal amounts of both, you just dose whatever your consumption rate is for each.

so yes you can manually dose CA and automate ALK.

mr. pluto
05/27/2009, 06:24 PM
if you have 1 pump only, alk is more important to automate over
a 24 hr. period. ca. you can split up and dose manually.

Stanley-Reefer
05/27/2009, 07:48 PM
What about you buffer part settling? I use Kent and I really shake the part B before measuring out the dose. I settles in the cup! Looks like using a doser would not be too accurate without a mixer in the container.

n8rad
05/27/2009, 09:12 PM
i use an aqualifter.

jim5280
05/27/2009, 09:30 PM
The pump gets here Friday, so I will check its accuracy throughout most of the day Saturday. I'm going to try using the pump for ALK only and dose CAL once in AM. I will give it a month or so and post results. Thanks, Jim.

spleify
05/27/2009, 10:12 PM
<a href=showthread.php?s=&postid=15087472#post15087472 target=_blank>Originally posted</a> by divewsharks
you don't have to dose equal amounts of both, you just dose whatever your consumption rate is for each.

so yes you can manually dose CA and automate ALK.

Its definitely recommended to dose both parts equally. You can dose one, more, a time or two two get your levels where you want them but it is then recommended to dose them equally.

Dont take my word for it read this;

http://reefkeeping.com/issues/2006-02/rhf/index.php

divewsharks
05/28/2009, 02:11 AM
<a href=showthread.php?s=&postid=15089205#post15089205 target=_blank>Originally posted</a> by spleify
Its definitely recommended to dose both parts equally. You can dose one, more, a time or two two get your levels where you want them but it is then recommended to dose them equally.

Dont take my word for it read this;

http://reefkeeping.com/issues/2006-02/rhf/index.php

long-term i would definitely agree, it best to add equal parts; but there are times when you need only a portion of the 2part, such as if if you use a salt mix that is high in calcium and lower in alk, and you don't supplement alk in your mixing tub; in this case you would likely need to back off on calcium supplementation and only dose the alk to get/maintain that at desired levels. hopefully at a point the calcium to come down to level and alk will raise to the appropriate levels, at which time you can/should dose the 2 portions equally.
If this becomes a continual pattern with the salt mix then one would need to supplement the new salt water to bring it to desired levels before adding to DT, at which time again one could/would dose the 2 parts equally.

hope this makes sense.

60Cubed
05/28/2009, 07:21 AM
You dose by the tanks demand. Not just equal parts........that's plain silly. I run a LM III for dosing mag. I used to run an Aquamedic twin. The problem with them is they do not restart after a power outage. So I switched to a more reliable controller. And the LM doses bases on mL per day. Not by seconds. You program the mL per day and it doses accordingly. The Aquamedic you have to figure out how many mL per minute and adjust it manually. That was kinda a PITA also.

I would dose both automatically with a doser. Why dose one manually and one with a pump? Once you get the alk stable you will start having a bigger flux in the cal level. I would set them both up and forget it! Automation is the best thing ever. I have my tank on autopilot.........

spleify
05/28/2009, 09:31 AM
<a href=showthread.php?s=&postid=15090440#post15090440 target=_blank>Originally posted</a> by 60Cubed
You dose by the tanks demand. Not just equal parts........that's plain silly.

Obviously you dose by tank demands, that is not the question here. And no its not silly to dose both parts equally, its chemistry.

polysynth
05/28/2009, 11:08 AM
I only pointed out dosing in 2 part in equal parts as something for jim5280 to consider since he's doing it one part manually. It's not "plain silly". I even stated for him to do whatever that works.

And if you're not dosing it in equal parts or one parameter is significantly higher than the other, there is possibility that you got some bicarbonate precipitation that you need to take care of.

d0ughb0y
05/28/2009, 12:22 PM
According to Randy, the consumption of ca and alk must be balanced (20 ppm of ca to 1 meq/l of alk (or 50ppm). As spleify mentioned, it is plain chemistry. So dosing balanced is appropriate. if the consumption is not balanced, then there is something wrong in the tank that needs to be fixed (as polysynth pointed out). What is silly is, say, to think that a drop of 50ppm of ca and a drop of 50ppm (1meg/l) of alk is the tank consumption/demand, but rather, the extra 30 ppm of ca is actually just precipitated.

if you are looking for a dosing pump that won't quite cost an arm and a leg, and is more accurate than an aqualifter, you can get the pumps from BRS ebay store. some DIY required though.

http://cgi.ebay.com/Bare-Bones-Peristaltic-Metering-Dosing-Pump-20ml-min_W0QQitemZ360154685886QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item53dae461be&_trksid=p4634.c0.m14.l1262&_trkparms=%7C301%3A0%7C293%3A3%7C294%3A30

A.VOID
05/28/2009, 12:33 PM
no one is using the medical pumps?

I use one to dose my 2 part over 24 hours. Love that thing. nice and simple and built like a tank

tegee
05/28/2009, 05:44 PM
<a href=showthread.php?s=&postid=15083488#post15083488 target=_blank>Originally posted</a> by cham
I've used aquamedic dosing pumps on all of my tanks for the past 3 years. I love them and never had a problem.

+1 never had a problem with them too other than the silicone tubes needing replacement every 6-8 months. Other than that 4+ years running strong. Mine are from ReefDosingPumps.com.

60Cubed
05/28/2009, 07:46 PM
<a href=showthread.php?s=&postid=15091607#post15091607 target=_blank>Originally posted</a> by polysynth
And if you're not dosing it in equal parts or one parameter is significantly higher than the other, there is possibility that you got some bicarbonate precipitation that you need to take care of.

So by this you would be saying that the cal demand could never be higher than the alk demand? And everytime you add a drop of cal you have to add a drop of buffer......?

In my experience the two part bottles never seemed to be empty at the same time! Call me crazy......but I never had any issues with my tank....and I'm no rookie to this hobby. Even though I don't know everything and am open to new things, saying these two must be added in equal parts or you got a problem is IMO a bit silly.

jim5280
05/28/2009, 07:55 PM
I've been dosing 45 ml ALK and 30 ml CAL daily. Cal- 450 ALK-10 Mg-1200 pH 7.9-8.15, can't figure out where extra ALK is being used.

usfpaul82
05/28/2009, 07:57 PM
Bulk Reef doser pumps are really the way to go for dosers in my opinion. I have been using them for a while now and they are perfect for the job. Just my opinion. And I see no issue with dosing ALK by pump and CA by hand. Would be easier to just get two pumps though. Its really nice not having to remember to do it every day.

redhanded77
05/28/2009, 07:57 PM
<a href=showthread.php?s=&postid=15094644#post15094644 target=_blank>Originally posted</a> by 60Cubed
So by this you would be saying that the cal demand could never be higher than the alk demand? And everytime you add a drop of cal you have to add a drop of buffer......?

In my experience the two part bottles never seemed to be empty at the same time! Call me crazy......but I never had any issues with my tank....and I'm no rookie to this hobby. Even though I don't know everything and am open to new things, saying these two must be added in equal parts or you got a problem is IMO a bit silly.

i agree. i use BRS dosing pumps, and i have to let one run longer than the other to keep things where they have to be.

d0ughb0y
05/28/2009, 08:54 PM
<a href=showthread.php?s=&postid=15094644#post15094644 target=_blank>Originally posted</a> by 60Cubed
So by this you would be saying that the cal demand could never be higher than the alk demand? And everytime you add a drop of cal you have to add a drop of buffer......?

In my experience the two part bottles never seemed to be empty at the same time! Call me crazy......but I never had any issues with my tank....and I'm no rookie to this hobby. Even though I don't know everything and am open to new things, saying these two must be added in equal parts or you got a problem is IMO a bit silly.

Randy states the chemistry part in his articles as When calcification takes place, two moles of alkalinity are lost for every one mole of calcium.

so if a tank consumes one more than the other, it simply means the rest are lost to precipitation, as the basic chemical equation for calcification is irrefutable.

To say on one's tank's calcification demand for calcium is higher is incorrect. But rather, one should say the depletion rate of calcium is higher, but the amount used for calcification will always be at a fixed ratio to alkalinity.

surely one can simply dose one higher than the other if the depletion rate is not balanced, but it can certainly be fixed to make the consumption balanced (just like NSW) so one can dose both in equal amounts.

vol_reefer
05/29/2009, 01:59 AM
Randy states the chemistry part in his articles as When calcification takes place, two moles of alkalinity are lost for every one mole of calcium.

so if a tank consumes one more than the other, it simply means the rest are lost to precipitation, as the basic chemical equation for calcification is irrefutable.

To say on one's tank's calcification demand for calcium is higher is incorrect. But rather, one should say the depletion rate of calcium is higher, but the amount used for calcification will always be at a fixed ratio to alkalinity.

surely one can simply dose one higher than the other if the depletion rate is not balanced, but it can certainly be fixed to make the consumption balanced (just like NSW) so one can dose both in equal amounts.

You know, I've always accepted that the two parts are used up exactly according to the stoichiometric ratio, as you state. But then there's something I have never quite figured out about this: It seems that most people observe that alk varies in our tanks on a much shorter timescale than Ca. For example, if my reservoirs of 2-part (I use an LM3 doser) run out and I forget to refill them right away, my alk gets out of whack much quicker than my Ca. But if the two parts are being used up equally during calcification, wouldn't we expect their levels to vary together in concert? There must be something I'm missing. Or is it just that the measurement units of the two test kits (I used dkH and ppm for alk and Ca, respectively) are making it look like they don't vary together? It would probably be better to be using moles for both to do this right...

Jeff (vol_reefer)

d0ughb0y
05/29/2009, 02:27 AM
I think one of Randy's articles addresses exactly that question.
It has something to do with NSW contains a lot more ca than alk, so it they are consume at that fixed ratio, alk will seem to fluctuate more.

1 meq/l = 2.8 dkh = 50ppm equivalent

so for normal 2.5meg/l alk to 420 ppm ca NSW values, that converts to about 125ppm alk only present in NSW. so for every 20 ppm ca consumption, 50 ppm alk will correspondingly be used.

two parts are formulated to have exactly the equivalent of 20ppm ca to 50 ppm alk part ratio for the same volume. Kalkwasser, contains that exact same ratio.

one thing for sure is , the chemical equation to combine
calcium chloride + sodium bicarbonate to produce the calcification (calcium carbonate) occurs at the fixed ratio. There is no such thing as on someone's tank, it uses more calcium chloride to produce the same amount of calcium carbonate, which I think is one of the earlier post was alluding to.

vol_reefer
05/29/2009, 09:45 AM
OK - I think that makes sense. Thanks for the explanation.

jahorgos
06/03/2009, 03:56 AM
Drews dosers from BRS! I swear by these. Definitely dose alk and cal automatically and you could even do mag although it seems to depreciate slowly so its not all that necessary really.

Automation when done right is the only way to go. More accurate and reliable.

P.S. Controls Engineer here :)

kmckay
06/04/2009, 09:50 PM
Also a big fan of automation for stability. I second what others have said; one should dose two part solutions in equal volumes daily. Over time, a real discrepancy between cal and alk will develop in most systems, but this occurs very slowly. These real discrepancies should be corrected by one time, calculated additions of the appropriate component while keeping the daily doses balanced. As stated already above, when short term apparent swings in alk occur without apparent change in Ca, these are actually not real imbalances but are an artifact in observation. This artifact comes from the relatively low concentration of bicarbonate (relative to Ca) in sea water and the fact that your test kit measures concentration. Any cause of true Ca-alk imbalance should be identified and corrected. This is all very well explained by Randy here:

http://reefkeeping.com/issues/2004-12/rhf/index.php

BTW, 60cubed, you are already making balanced additions daily with your calcium reactor and with your kalkreactor. So you must be using two part to correct imbalances, where it is appropriate to dose only one or the other. :)