Overview Kalkwasser is limewater, a saturated solution of calcium hydroxide in water. When applied to marine aquariums, it replenishes calcium and maintains alkalinity, benefiting invertebrates such as coral and clams, and calcareous algae that build skeletons, shells and crusts from calcium carbonate.
It helps maintain aquarium pH and precipitates phosphates. It also reacts with fatty acids and other organic compounds, and this plus the naturally boosted pH enhances protein skimming.
Instructions It’s easy to make Kalkwasser! Just add 2 tsps. of calcium supplement mix per gallon of cool freshwater in a closed container and stir. When the undissolved powder settles, the clear liquid above it is a saturated solution of Kalkwasser.