The depth of the flooring depends on the type of plants: plants with strong roots require a planting depth of at least eight centimetres. Ideally, you will fill the flooring so that it rises towards the rear wall of the aquarium. The higher layer of aquarium floor in the back offers the plants used there more space for their roots, any dirt that occurs slides forward down the slope, where it can be quickly found and easily removed. At the lowest point in the foreground, the filling height of the aquatic gravel should still be at least five centimetres.