Yep...I know..since kalkwasser is mainly Ca(OH2)....the Ca will increase calcium level..the OH anion will increase alkalinity.
But for...carbonate hardness...that one cannot be maintained by Ca(OH)2 can it? Unless I bubble CO2 or something into my water to form CaCO3? For now I'm using the Reef builder. No plan to inject CO2...dun wan any freak accidents to occur.