# Best way to add Calcium?



## niko (Jan 28, 2004)

The last few months I've come to the conclusion that adding only baking soda to raise the KH is not the greatest idea.

Adding baking soda is very easy but from my experience Calcium is much more important. Adding liquid calcium meant for reef tanks had not failed to produce visible changes in 3 of my tanks.

My question is what is the best, most acurate, and also cheapest method of adding Calcium?

--Nikolay


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## Phil Edwards (Jan 22, 2004)

Did you try Turbo-Calcium? I've had great results with it. While expensive per container, it'll last a long time and is cheap over the long term. 

Best,
Phil


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## ShaneSmith (Feb 15, 2004)

Aqui sells calcium carbonate tabs on his website (Which i dont have the address for now). Niko and Phil, What are your GH's?


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## dennis (Mar 1, 2004)

Guiancarlo uses Calcium tablets from the drug store. Apparently the generic brands are pure calcium carbonate. BTW, sorry if I spelled your name wrong.


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## Phil Edwards (Jan 22, 2004)

Shane,

Coming out of the tap my GH is about 1. I don't think I add enough Ca and Mg to affect it for more than a day after supplimentation.

Best,
Phil


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## gnome (Jan 27, 2004)

A long time ago I asked Erik Leung how he raises his GH (we're both cursed with this weird Bay Area water). He said that he gets CaCO3 in the pure, powder form from brewing supply stores. I recently ordered the following from an on-line supplier:

CaCO3 ("precipitated chalk")
CaSO4 ("gypsum")
KHCO3 ("acid-reducing crystals")
MgSO4 (you can, of course, get it at any drugstore as "epsom salt")

I think Erik said that he aims for a GH of 4-5, and uses 1:4 Mg-to-Ca ratio. He doses at night and by morning, the cloudiness from the CaCO3 is gone. I've discussed the use of gypsum with somebody else who says that it's just as difficult to dissolve as the carbonate, but if you want to raise the GH and not the KH, this is what should be used. 

I have not yet had a chance to use either of the calcium salts, so I don't know how much stuff will raise the hardness by how many degrees per unit volume. These salts may or may not be very economical for aquarium use. I don't know, yet.

-Naomi


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## ShaneSmith (Feb 15, 2004)

What about CaO (Burned Lime) I hear its a oxidator but i dont see how oxygen could affect things.


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## Phil Edwards (Jan 22, 2004)

Shane,

When the term "Oxidizer" is used it's referring to the chemical transfer of electrons. When something is oxidized it loses (an) electron(s). The substance that gains the electron(s) is said to be "reduced" because the overall charge of the species is reduced by the number of electrons gained.

That's why laterite and clay-rich substrates are important in aquatic ecosystems. Clay has an overall negative charge and accepts ions with overall positive charges, such as Ammonium and Phosphate. We say that laterite is a "reducing substrate" because when it bonds with Ammonium (NH4+) it loses it reduces the Ammonium's charge by donating an electron when the clay and NH4+ bond. 

Best,
Phil


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## gnome (Jan 27, 2004)

Sorry, I don't mean to be splitting root hairs, but phosphate (PO4)3- is an anion (negatively charged). But that's about as much as I can remember from my five miserable years as a chemistry major :roll: . 

-Naomi


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