# Calcium sources



## zelmo (Oct 21, 2005)

GW sells Calcium Nitrate, Calcium Carbonate, Calcium Chloride, and Calcium Sulfate. Do I assume that since the GH booster contains Calcium Sulfate this is the best compound to use for the calcium source?


----------



## bigstick120 (Mar 8, 2005)

If you just want to add calcium get CACL2. The GH booster I assume also has MG in it


----------



## Edward (May 25, 2004)

zelmo said:


> Do I assume that since the GH booster contains Calcium Sulfate this is the best compound to use for the calcium source?


 Of course not. Years ago I posted a recipe for a Discus Mix. This product was used for breeding discus in demineralized water with great success. Long term tests on aquatic plants made this mix the best choice. 

*Discus Mix:*
30 grams CaSO4
10 grams CaCl2.2H2O
10 grams MgSO4
15 grams NaHCO3 baking soda

Dose dry to desired Ca levels.


----------



## Laith (Sep 4, 2004)

Just be aware that the Discus Mix will also raise KH...


----------



## zelmo (Oct 21, 2005)

bigstick120 said:


> If you just want to add calcium get CACL2. The GH booster I assume also has MG in it


Thank you. CACL2 it is.


----------



## Glouglou (Feb 21, 2006)

*Raising Ca*

I can see a lot of post around with stunted and distorted growing tip. Calcium deficiency or uptake blockage seem to correspond to that problem.

Tell me if I am wrong?
a) What I can see around is that the calcium uptake is not completely understood
b)The optimal PH for uptake is around 6.6 an decrease with lower PH
c) high magnesium reduce calcium uptake
d) high potassium and nitrogen can reduce calcium uptake
e) problem with calcium first appear within rapidly developing, low-transpiring plants.(Ludwigia can be in this category?)

1- Do you recommend to have a calcium test kit? 
2- What is the best product to raise Ca without raising KH
3- A ratio of 3:1 to 4:1 (Calcium/magnesium) is found in natural water


----------



## BryceM (Nov 6, 2005)

A little chemistry.....

Natural bodies of water get most of their hardness from passing on/over/through rocks containing calcium carbonate (CaCO3). They also get calcium and magnesium from an enormous variety of other salts.

Each calcium-containing compound has advantages and disadvantages. You just need to pick one that will accomplish what you're trying to do:

CaCl2 - Often sold as sidewalk ice-dissolver. Check the label. Inexpensive. Adds chloride ions, which some see as a potential issue. Many people use it without problems. It usually exists in a hydrated form (CaCl2-2H2O), meaning it's complexed with two water molecules, so remember to account for that when doing molecular-weight calculations.

Ca(NO3)2 - This is potentially useful in some situations where you're trying to dose calcium and nitrate at the same time. Usually, KNO3 does just fine for supplying nitrates since K is also a desirable element, but to each his own....

CaCO3 - Potentially the most "natural" form of calcium. This is essentially ground chalk. It's also quite inexpensive, widely available and works fine. It will raise both GH and KH which can be good or bad, depending on what you're trying to accomplish. The biggest strike against this compound is that it dissolves quite slowly in water. It will often cloud the tank for several hours. There are ways around this, like dosing at lights-out, but it can be cumbersome.

CaSO4 - This is the form supplied in GW's GH Booster and also in Seachem's Equilibrium. It dissolves rapidly, it adds sulfate which plants require in small doses and tollerate quite well even when it's abundant.

Greg Watson's GH booster is for all intents and purposes a poorman's version of Seachem's Equilibrium. They both contain CaSO4, MgSO4, K2SO4, and small but important quantities of manganese and iron. The Ca/Mg ratio is worked out to provide roughly a 3:1 or 4:1 dose which is supposedly ideal. I've used them both to reconstitue RO water and they both seem to work fine. I usually end up supplementing with a bit of extra Mg though.


----------



## Glouglou (Feb 21, 2006)

*Thanks Guaiac*

About the calcium test kit. Maybe it can be interesting to know the calcium content and I beleive that if you know your calcium content, you should be able to average your magnesium content (if everything is in balance).

I remember that formula: (answer is approx.)
(GH (Ca + Mg) in ppm) - (2.5 x KH (Ca) in ppm) divide by 4.1 should give an approximation of your magnesium...


----------



## BryceM (Nov 6, 2005)

For those who are really interested about knowing what is going on with regards to general hardness, Lamotte makes a fantastic test kit.

It's Model PHT-CM-DR-LT, Code 4824-DR-LT. I think I paid about $45 for it. It provides a test for GH, accurate to 4 ppm and a test for Ca, also accurate to 4 ppm. If you subtract the two numbers the remaining hardness can be assumed to come from Mg. This assumption isn't much of a stretch, since Mg probably accounts for 99% of the general hardness that isn't from Ca.

I find it useful for reconstituting RO water. Once you have a mix and dosing plan figured out it only takes a few spot checks here and there to keep things in the sweet spot.


----------



## Edward (May 25, 2004)

Another great way is to use a 'High-Flow' RO unit. Because such filtration system removes only ~75% of minerals there is no need to add any calcium, backing soda etc. I use 2x100 gallon per day High-Flow RO for aquariums and 2x60 gallon per day Hi-S RO for drinking with great results. Highly recommended. 

Here is Ca / Mg calculator.


----------



## MatPat (Mar 22, 2004)

guaiac_boy said:


> For those who are really interested about knowing what is going on with regards to general hardness, Lamotte makes a fantastic test kit.
> 
> It's Model PHT-CM-DR-LT, Code 4824-DR-LT. I think I paid about $45 for it. It provides a test for GH, accurate to 4 ppm and a test for Ca, also accurate to 4 ppm. If you subtract the two numbers the remaining hardness can be assumed to come from Mg. This assumption isn't much of a stretch, since Mg probably accounts for 99% of the general hardness that isn't from Ca.
> 
> I find it useful for reconstituting RO water. Once you have a mix and dosing plan figured out it only takes a few spot checks here and there to keep things in the sweet spot.


I have to second the use of this kit. It is an easy to use test kit and it pretty accurate out of the box. It may seem a bit expensive at first but you can get quite a few tests out of it if your water isn't hard, which shouldn't be the case when reconstituting RO or RO/DI water. You also effectively get three test kits, GH, Ca and MG which puts it inline, price wise, with most other test kits out there


----------



## Glouglou (Feb 21, 2006)

*Calcium*

I find some calcium in pharmacy, 120 caplet, 500mg each Elemental calcium (from carbonate) 5 dollars canadian.


----------



## Glouglou (Feb 21, 2006)

*Calcium source*

Well the Calcium (from carbonate) from my precedent post will probably raise the Alkalinity (KH)

If I don't want to raise my KH, what is suggest on most of the post is:

Calcium Sulfate (CaSo4) = Do not raise KH and add some So4 needed for plants

Calcium Chloride (CaCl2) = Do not raise KH and add some Cl2 needed for plants

I already add my magnesium with So4-> MgSo4 and have no source of Cl2

Should I go with Cacl2 ?
and where do you find those coumpound ?

I already know that Cacl2 is use in the pickling process and CaSo4 is use to make Tofu


----------



## BryceM (Nov 6, 2005)

It's pretty much doesn't matter. Either will be fine. I use CaSO4. Some people theorize that Cl can be potentially harmful in high doses, but plenty of people use it.


----------



## handimn1 (Mar 24, 2006)

How do you get the KH and the GH to lower, mine is way to high?


----------



## Laith (Sep 4, 2004)

handimn1 said:


> How do you get the KH and the GH to lower, mine is way to high?


How high is it?

The only way to lower those parameters is to us Reverse Osmosis water which has a KH and GH of 0. You'd need to purchase an RO unit. The best way to use the RO water is to mix it with tap water in order to get the KH and GH levels you want.

However, you may not need to have lower KH and GH...


----------

