Seachem Reef Kalkwasser™ is a high-purity calcium hydroxide (Ca(OH)_2) designed to maintain calcium concentrations and carbonate alkalinity in reef aquariums. Known for its exceptional solubility and purity, it is the preferred choice for hobbyists utilizing the "Kalkwasser Method" to promote coral calcification and coralline algae growth. By providing both calcium and carbonates in a balanced ratio, it supports the skeletal development of stony corals while simultaneously assisting in the maintenance of a stable, elevated pH (8.3–8.4).
Reef Kalkwasser™ provides more than just the building blocks for corals; it acts as a comprehensive tool for maintaining a healthy reef environment.
Balanced Ionic Support: Delivers calcium and alkalinity in the same proportions used by corals, simplifying the maintenance of these critical parameters.
Natural pH Booster: Its highly alkaline nature helps neutralize organic acids, making it an excellent solution for aquariums struggling with chronically low pH.
Phosphate Precipitation: When dripped into the aquarium, it reacts with phosphates to form insoluble calcium phosphate, which is then removed by protein skimming or mechanical filtration.
High Purity Standards: Carefully processed to ensure it is free from the heavy metal contaminants often found in lower-grade lime products.
Encourages Coralline Algae: Maintains the specific water chemistry required for the rapid spread of pink and purple coralline algae across rockwork.
How do I prepare Seachem Reef Kalkwasser™?
Add 3 g (approx. 1 teaspoon) to 4 liters (1 US gallon) of freshwater and mix vigorously. Allow the solution to sit until a clear liquid forms with a white crust on top; only use the clear liquid (the "limewater") for your aquarium.
How should I add it to my tank?
Never add the powder directly to the aquarium. It must be dripped slowly into a high-flow area—ideally at night—to prevent sudden pH spikes that could stress or kill livestock.
Can I mix this with my top-off water?
Yes, it is commonly added to Auto Top-Off (ATO) reservoirs. However, ensure the intake pump is positioned above the bottom sediment to prevent dosing undissolved solids into the tank.
Seachem Reef Advantage Magnesium™: Essential to use alongside Kalkwasser, as magnesium is not provided by this supplement and is required to prevent calcium precipitation.
Seachem Reef Buffer™: Use to further stabilize pH if Kalkwasser alone is not maintaining your target 8.3 level.
Seachem MultiTest™ Calcium: A high-precision test kit to ensure your Kalkwasser drip is meeting the specific calcium demands of your coral load.
