Let's talk about Alkalinity, Calcium and Magnesium in an SPS Tank
- Thread starter JB NY
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JetCat USA
In Memoriam
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.
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
Active member
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
New member
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.
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
New member
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....
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
New member
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
Coral Killer
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.
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.
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.
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.
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
New member
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.
"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
New member
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
Coral Killer
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
Active member
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.
Code:
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:1320I 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.
Serioussnaps
New member
FWIW, your MG levels can drop somewhat faster in your system if you use alot of kalkwasser/lime. Just thought I would add that.
Aquarist007
New member
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
New member
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
Active member
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.
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
New member
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?
