SubstrateSource natural sands come in various shades and can be easily mixed to create completely new looks. Our sands do not discolor, fade, or leach chemicals like low-quality epoxy coated sands can. SubstrateSource sands are popular for use in various crafts and sand art. Although all of our substrates have been pre-rinsed, we recommend that you rinse once before using to remove any dust particles that may have occurred during shipping. Also, FRESHWATER AQUARIUM SAFE!