Chemist genious needed, Calcium citrate

[fish_4_all]

Calcium citrate pure powder. Does anyone know how to dissolve it and what the overall analysis is going to be for dosing? All that I need to know is pH and GH effects.

If it helps, the stuff I have analyzes this way:
1 tsp of powder is 700mg of calcium and 2300mg of citrate

 

[7Enigma]

I'll let you know on Monday when I get into the lab. Is this laboratory grade?

I need to know from you how much GH (from the calcium) are you looking to add to your tank, and what your tank size is. For example, you have a 10 gallon tank that you want to raise the GH 5 degrees. That will give me a better idea of the goal you require.

The pH affect is something none of us can do for you. Your water supply will have a specific starting KH value, plus whatever you have added and any other buffering substances present in the tank.

What I would recommend is after you reply with the GH you desire from calcium, I'll figure out how much you should add to the tank (on Monday), and then you do a test with your tank water to determine if there will be a large pH swing (say do a 25% PWC into a bucket and add the amount of calcium citrate for that amount of water and check the pH). My guess at this point would be that the amount of calcium citrate you will need to add will not change the pH of the tank by more than 0.3pH units (probably less), which is essentially impossible to measure without a calibrated liquid pH meter. Strips or a liquid reagent test kit will probably show no appreciable change in color.

HTH,

justin

 

[fish_4_all]

This is Now Foods grade, I bought it from a health food store and it is as a calcium suppliment but it is absolutely pure Calcium citrate or so they say.

10 gallon tanks, is all I have set up right now. As for my GH, 3:1 Calcium to Mg so target 8 would mean 6dGH from Calcium and 2 from Mg. My tanks are already pH 6.6 so I don't want to lower it too much. Tap is 7.0 pH.

Thanks 7Enigma, I still haven't gotten it to dossolve so I think dosing dry is the way to go unless I want mix it by the gallon.

BTW, the sprinkles I have added being on the very low side have had no effect on pH and have raised my GH by about 1-2 points. although it is really hard to be really accurate between 1-2 drops.

I did find this if it means anything, solubility is .85g/100ml.

 

[7Enigma]

This is Now Foods grade, I bought it from a health food store and it is as a calcium suppliment but it is absolutely pure Calcium citrate or so they say.

10 gallon tanks, is all I have set up right now. As for my GH, 3:1 Calcium to Mg so target 8 would mean 6dGH from Calcium and 2 from Mg. My tanks are already pH 6.6 so I don't want to lower it too much. Tap is 7.0 pH.

Thanks 7Enigma, I still haven't gotten it to dossolve so I think dosing dry is the way to go unless I want mix it by the gallon.

BTW, the sprinkles I have added being on the very low side have had no effect on pH and have raised my KH by about 1-2 points. although it is really hard to be really accurate between 1-2 drops.

I did find this if it means anything, solubility is .85g/100ml.

With most chemicals that are poorly soluble a pH change is needed to get it to solubilize (or using an organic solvent but we definately don't want to do that).

When you say you added a small amount are you talking about the citrate or baking soda? You mention that your KH is raised by 1-2points which will only happen if there is carbonate present in the mixture. Did you really mean GH?

Thank you very much for the solubility info because that is indeed quite low (essentially 1% soluble). If you use a 5gallon bucket for PWC's (that's what I use for my 10 and 20 gallon tanks) you will easily be able to add the calcium citrate and have it dissolve since with that solublility you could add quite a bit and still have it go into solution.

Note for myself:

-10gallon tank
-increase GH by 6 degrees
-~1% solubility

 

[fish_4_all]

Sorry, my GH went up, not my KH. I think my brain takes vacations in my tanks.

 

[Lonewolfblue]

Sorry, my GH went up, not my KH. I think my brain takes vacations in my tanks.

Same here, lol...

 

[czcz]

(not a chemistry genious.)

If it's 700mg Ca per teaspoon, one teaspoon adds 18.5ppm Ca into ten gallons.

700mg Ca / (10gal * 3.785L/gal) = 18.494mg/L Ca ~ 18.5ppm Ca.

You could just make your Ca 3-4 times whatever your Mg dosing is and not care worry about resulting dGH. This is the better way to do it since ppm is more usable (and easier) for your purposes.

 

[fish_4_all]

Good thought, it may work that way, I hope it does. The only problem is, how much is the Calcium citrate going to drop my pH for each teaspoon dosed?

Going 3:1, I would dose .5tsp MgSO4 and 1 heaping tsp Calcium Citrate to get the ratio. The major worries are these:
Doing a 50% water change, if my GH is now 30 and drops to 15, what will be the short term effect until the calcium citrate can dissolve fully? The other is how much will my Ph drop when I add it? I can deal with .1-.2 total drop but anything more and I am too low for my comfort already having a steady pH of 6.6 after equilization.

Like I said, a really good idea and I will do it assuming that my GH isn't some huge number and my pH doesn't plummet killing all my fish. If 1 tsp only changes my GH by 3-8 points then and my pH by less than .2 then I will use it straight up like that. If I have to dose something like 0.0025 grams because of the effects, I will use it for my orange juice and buy GH booster from gregs or find another source.

I just want to be safe. I wouldn't care if it was just plants and a few snails but my BN and cories might care and my wife would care if I killed her swords. I hope it doesn't dissolve too slowly but it won't dissolve as fast as MgSO4 so effects would be gradual which is a good thing.

Does anyone know the calculation for GH from ppm?

BTW, thanks for the calculation, I need to remember that one.

 

[czcz]

I'm not sure it will affect your pH since Citrate isn't Citric acid, but again am no chemistry expert. Citric acid is a weak acid anyway and you could probably ignore the impact if you also ignore the results from the pH/KH/CO2 table. Personally I also don't think you should be worried about pH 6.4 unless you keep Africans or something, fwiw.

If worried about the GH swing, you could dissolve the calcium citrate before putting it into the tank. Wikipedia says you can dissolve 95mg of Calcium citrate in every 100mLs, but maybe that food grade stuff has something in it preventing this.

If you really want to be safe you should probably bite the bullet and get CaSO4 or CaCl from Greg. Or get GH Booster, especially since it also adds Mg, K, and Fe and saves you some time in the long run.

Its 17.9ppm CaCO3 per dGH, and your GH test is really measuring using this standard, not Mg and Ca, so calculating GH from Mg and Ca is difficult (and over my head). Here's the kirb and Salt's calcs to get you started. Just using Mg and Ca ppm makes a lot more sense to me.

 

[Lonewolfblue]

As for the calculation, it's the same as kh. The gh or kh is multiplied by .056 to get the degrees. So if the gh is 100, then it's 5.6 degrees.

That's per the instructions in my Hagen kit anyways.

 

[7Enigma]

Doing a 50% water change, if my GH is now 30 and drops to 15, what will be the short term effect until the calcium citrate can dissolve fully?

If you are doing a PWC into a bucket (I would assume you might be since its only a 10gallon tank), you should have no problem with it completely dissolving. Based on the ~1% solubility, you can easily get a full teaspoon to go into solution in a gallon. If this is a 10gallon tank, you can easily do a 50% PWC with a single change with a 5gallon bucket (like I use), and then dose the GH by way of calcium and Mg for the 50% PWC. This should keep the level constant within reason (a small shift either direction will not bother the fish, its the large shifts of multiple degrees that can cause problems).

And I cannot find calcium citrate to test for you, but those estimates should be more than enough to get what you are looking for. I'd recommend (as I said before) to do a PWC of about 50% into a bucket, measure the GH and pH of the bucket water, then test dose your calcium citrate and completely dissolve the citrate in it (I'd let it sit for 10minutes, or constantly stir it until you are confident it is mixed fully). Then measure your GH and pH to see if the shift is appropriate (ie GH went up enough and pH didn't crash).

 

[fish_4_all]

Sorry, had to make major changes, is 95 mg instead of 0.95 mg / 100 ml. Must have seen it wrong. Thankfully it was easy to change.

Ok, here is what I figured out. With a 95mg/100ml, It comes out to just about 36,000mg that will dissolve in 10 gallons.

(3785.4ml/1gal) * (95mg/100ml) * 10gal = 35,961mg soluable

1 tsp. would give me 18.5 ppm Ca
1 tsp = 700mg Ca / (10gal * 3.785L/gal) = 18.494mg/L Ca ~ 18.5ppm Ca.

So in a partial water change, 5 gallon max, I should dissolve 1/2 tsp in the buckets.


Then I would dose Mg as follows:
18.5ppm calcium at 3:1/4:1 Ca:Mg I would dose 6.17-4.625 ppm Mg or ~2 tsp, 5.66ppm.

 

[czcz]

The solubility for Calcium citrate is 95mg per 100mL, not 0.95mg, so you should be able to safely dissolve 35960mg of it into 10gal: more than enough for your purposes. Otherwise your math is good: good job.

You want the 3-4:1 ratio, but in the end you want Ca around 30-40 and your Mg around 5-10. So go back to your original plan of a heaping tsp of Calcium citrate and 1/2tsp MgSO4, or just bump up both a little.

 

[fish_4_all]

Your right, it was a major error in my part. I read it wrong or wrote it down wrong, something.

I can't dissolve Calcium citrate in my tap water, it is neutral, the calcium citrate require an acid to dissolve, won't even dissolve on my fingers. No biggy, just means I have to add it to my tank directly.

Glad you caught that. Well I did to but anyway. I even want to wikapedia yesterday and wrote it dorectly form there! Must be a sign of my 85 year old mind in a 34 year old body.

Thank both of you, the only part you missed is it won't dissolve in neutral water, which I had to experiment with and find out and search really hard to find. Dissolves best in normal gastric acids according to the nutrition sites I found. The information I found states there is a negligable pH effects but I will have to test that in my tanks.

I have 1/8/ tsp sitting in one gallon and it still looks the same with absolutely no change in GH or pH. Hot tap water so that confirms the needs for an acid to dissolve it. Thankfully my tanks are pH 6.6.

30-40ppm Ca and 5-10 Mg, so 2 tsp of each. Adding the MgSO4 to my buckets to make sure no major GH change then adding the Ca to the tanks. Will see how it works, shouldn't hurt the fish but actually help them. Could explain the slow growth from my more ornate stem plants.

 

[czcz]

Great work. 2 teaspoons of MgSO4 adds 28ppm Mg to 10gals though using Chuck's calc.

I'm a little worried about the Calcium citrate only dissolving in an acid -- do you think pH 6.6 is enough? How about pumping quick and dirty DIY CO2 into your mixing bucket to see what happens?

 

[fish_4_all]

Ok, I am glad you are watching me, I need it today. .5 tsp MgSO4 and 2 tsp Ca2(C6H8O7)2, calcium citrate. That is better I hope. I left it for a 55 gallon instead of 10. I think I need more caffiene, or maybe less!

As for dissolving, I don't know. I dosed 1/8 tsp in my one tank and it has dissolved about 75% of it in about an hour. Is a slow process. If I can get it to dissolve in quantity doing a quicky DIY CO2 and it will stay dissolved then I will just make up a solution and be happy. Maybe I can try dissolving it in soda water for making a solution? Assuming nothing but water and CO2 and nothing that won'y be useful or harmful.

Thanks for catching my error, again. See why I always ask so many questions, I can never get it right the first, second or third time!

One other question, is this a once a week thing or every other day?

 

[czcz]

No problem -- its tricky stuff and we're all learning. I doubt the uptake of Mg and Ca is the same, so I would split up the above equally to two or so doses. This reasonably falls in the estimative part of EI for me, while taking steps to maintain the ratio and somewhat stabilize GH change. But this is only a guess until corrected.

 

[fish_4_all]

This is why i didn't become a chemist. I always got the numbers right but rarely got the decimal or units right. Thats what I get for wanting to become and engineer and trying to use metric units!