Hydro-carbonate is a natural product and is used in calcium reactors, hardening up filters, but also in bio filters and as bottom ground for marine and Malawi/Tanganika aquariums. It creates natural calcium - carbonic acid equilibrium in all aquariums with alkaline pH value. In calcium-reactors, that are supplied with CO2 , it dissolves completely forming Calcium-bi-carbonate Available in 3 grain sizes. Packing:

• Fine ( 1 - 2 mm) for hardening-up filters  
• Medium ( 3 - 5 mm) for calcium reactors  
• Coarse (12 - 15 mm) as filter material