Golden Sand GravelGolden Sand from Dymax is 2 4mm sized mixed natural gravel (not sand, despite the given name), ideal for creating a thick layer to cover and cap bottom fertilizing substrates (such as Tropica Substrate). Ununiform stones in different shades, Ideal for freshwater aquaria. Note: Product images are for illustrative purposes only. Due to differences in monitors, colors of actual product may slightly appear different to the shade shown on the site.