Kalk ?

[jgrog76]

I am using kalk in an ato for the majority of my dosing. I am up to full saturation 2 tsp gal now. Even when I was at 1tsp gal some Kalk would end up not disolving and settling to the bottom. Why doesn't it disolve completely like other additives? I am using ro/di to mix it so I know it is not water impurities falling out of solution from the high ph.

 

[HighlandReefer]

Kalk water will precipitate out impurities when mixed with rodi water, which will settle to the bottom. In addition, you may get calcium carbonate precipitating out since there is usually CO2 in the rodi water. You do not want to dose the solids found at the bottom of the kalk mixing container, since they are impurities which are always present to some degree in the kalk powder. This is normal and a definite advantage since kalk water is self cleaning in that sense as opposed to the other supplements used.

Randy explains it in this article:

The Self Purification of Limewater (Kalkwasser)
http://www.advancedaquarist.com/issues/may2003/chem.htm

 

[bertoni]

I agree that the kalk might have some impurities, including calcium carbonate, since kalk will convert slowly to calcium carbonate when exposed to air and water. Sometimes, the solutions seem cloudy, and we don't know why, though. I wouldn't worry much, personally.