Steve,
I like Salifert for everything.
Dosing Kalkwasser will depend on your demand and evaporation. If your demand is too high, and your evaporation is too low, you might not be able to keep up. It also depends on your attention span. Kalkwasser is something you might have to dose everyday, but you have to replace evaporated water everyday anyway.
You can also dose Calcium Chloride. It a little trickier, but will raise Ca levels pretty fast. Without water changes, it can throw off your salts over time. But it takes a long time.
Some people have to use both.
Either way will work. Kalkwasser has the added benefit of adding buffers. Using Ca Chloride alone adds no buffers for alk.
You are thinking about alk too, right?
Don't forget your Ca levels are dependent on your alk levels and visa versa.
HTH
Jerel
PS someone else jump in here
