Kalkwasser

Peter Pan wrote:
What is Kalkwaser used for? I have FOWLR I Knows its for Corals but what
does it do?

You can mix it with RO/DI water for make up water. In solution, it
creates Calcium hydroxide, so it replenishes Ca+ ions. As it's very
basic, it's best to drip it in using a drip gate or using a top off
device or mix it with the effluent from a calcium reactor.

It will help your coralline grow if you have it. It will also react
with phosphate and participate out of solution, so it keeps the
phosphate under control as well. When I was dealing with hair algae, it
really helped knock back the growth.

--Kurt