Fritz Pro Carbon AG:
Professional quality charcoal designed for use in aquaculture. High adsorption capacity. Does not release phosphates. It is a premium quality bituminous granular activated carbon. Fritz uses a patented high temperature steam activation process that achieves superior pore space. It is then washed with hydrochloric acid to reduce the water and improve its purity. With this we create a carbon "sponge" of great porosity, very high adsorption, great mechanical hardness and chemical stability.
Add approx. Half a glass for every 78 liters. To keep the charcoal activated, it has not been washed so before using wash thoroughly with cold water. Store in a cool, dark place. Keep out of the reach of children.