sera Gravel is CO2 proof and neutral towards water, i.e. it has no influence on water parameters and does not tint the water. Due to a grain size of 0 - 2 mm, plants can grow on excellently. Due to being round grained, the colored gravel is also suitable for keeping bottom oriented fish such as catfish.
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.