DENNERLE crystal quartz gravel, diamond black

Dennerle quartz gravel is suitable for bottom-dwelling fish. As their sensitive barbels could be injured by the sharp edges of gravel grains while foraging, Dennerle's fine gravel grains are suitable. The gravel grains are free of hardness; they have a grain size of 1-2 mm, are rounded in a ball mill and dyed with food coloring. They should be rinsed thoroughly before use.