RowaKalk 1000ml is a 98.2% pure form of calcium hydroxide for making up kalkwasser (limewater) and using in kalkwasser stirrers.

Kalkwasser is a solution made by dissolving Calcium Hydroxide in water. The resultant fresh solution is alkaline with a pH of 12.4 and contains a ready supply of both Calcium ions and Carbonate ions.

The Calcium ions are available to the corals for healthy growth and the Carbonate ions help to buffer the pH. Kalkwasser contains no other ions that would otherwise cause an imbalance in the water chemistry.

Kalkwasser is ideally dosed after the lights have gone out on the aquarium to counter the natural drop in pH which occurs when photosynthesis stops.