# How to make CaCO3 dissolve quickly



## kekon (Aug 1, 2005)

I know many folks using pure RO water are very reluctant about using CaCO3 because of it's hard solubility. I found a way to make it dissolve quickly and easily. Typical CaCO3 is sold in a form that resembles very fine seeds of sand (precipitated form). To increase its solubility it must be powdered to dust. The CaCO3 dust when poured into the tank dissolves quite quickly; most of it dissolves immediately, some of (about 20..30%) settles on the bottom and water turns a bit murky. The murky water will be clear within 1..2 hours. The rest of CaCO3 that stays on the tank bottom will dissolve during the night. 
I just used a kitchen mortar to powder CaCO3. I put small amount of it (2..3 grams) into the bowl and powder it by pressing the mortar stick as hard as possible. At the beginning it seems that nothing happens. However after about a minute (when CaCO3 hast just been powdered) it will simply "climb" on the wall of the bowl. 
Now i use only CaCO3 as a source of Ca (and very small amount of CaCl2 or even NaCl as a source of chlorides) and it seems it works better than CaSO4 and baking soda which introduce much suplhates and sodium.


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