Calcium carbonate 5kg (100% organic from fossil marine animals)

100% organic from fossil marine animals.
Highly bioactive.
Finely ground and easily soluble in water.

Adding calcium carbonate increases the carbonate hardness and thus the pH value in the system. Due to the buffering effect, an overdose is harmless. As the pH value increases, calcium carbonate becomes less soluble in water, so the pH value no longer increases and only when the pH value would fall again does the calcium carbonate stabilize the pH value against a decrease. This makes managing the pH much easier and safer.