sera Gravel Brown is CO2 proof and neutral towards water, i.e. it has no influence on water parameters and does not tint the water. It consists of ground lava rock, and provides ideal space for settling by useful bacteria due to being open and porous. It is thus effective as a supportive natural biological filter medium. At the same time it provides plants with optimal preconditions for developing strong roots.
To calculate the amount of gravel needed for your aquarium;
Tank Length x Tank Width x Gravel Depth divided by 1000.
eg (60x30x4cm)/1000 = 7.2 Litres of Gravel.