Dennerle quartz gravel is a classic in the range and has been one of the best gravels for aquariums for many decades. Its excellent appearance and perfect biological function, which does not harden the water, are likely unique in this combination. It is lightfast and CO2 resistant, can be reused, and retains its color even after years. Due to the iron oxide coloring, the quartz gravel is water neutral and guaranteed free of pollutants. The grain size of 1 – 2 mm is suitable for bottom-dwelling fish and reduces the risk of dirt accumulating in the gaps. The fine quartz gravel is also very suitable for plants with fine roots. The use of rounded grains greatly reduces the risk of aquarium animals injuring themselves. The very small gaps that do exist provide an ideal settlement area for important bacteria. Dennerle quartz gravel does not need to be pre-washed, except for the color natural white.