From what I have read ( I do not dose
Kalk yet )
kalk is used to maintain calcium and
Alk. which also helps balance your
PH. Dosing
Kalk Is better than the two part additives, but if you have a large
Ca. uptake ( IE. lots of stony corals or clams ) then it might not be enough. so you would then need a
Ca reactor
HTH
