Crushed oyster shell is essential for raising the water hardness in aquariums. To maintain a stable KH which in turn helps to keep a stable pH. The shell grit may be used in aquariums over short or long periods to alter the hardness to a level where a buffer can be used. It is advisable in fresh water aquariums to place the grit in a nylon bag so it can be removed once the level required is achieved.
Size: 500g