Also known as limewater or kalkwasser, calcium is an important and essential reef tank additive. Here is information all about calcium, how to mix and add it, measure carbonate calcium (dKH or KH) hardness levels, and more.
From your About Guides, Don Carner gives a product review on the Knop Calcium Reactor, a product that he himself used for many years and gives a 10 rating on!
When it comes to the growth and health of corals and other invertebrates in reef tanks, most aquarists have found the best results are acquired by dosing the aquarium with calcium, liquid vitamins and other beneficial supplements on a regular, if not daily basis. You can take the "Oops, I forgot to dose my tank", vacation concerns, and other tank maintenance worries out of performing this task by installing an automatic doser to provide a consistantly measured and timed additive dosage.