Desgined for planted aquariums and aquascaping, Controsand by Ultum Nature Systems is a natural substrate blended for freshwater aquariums and terrariums, Controsand is safe for fish/invertabrates/reptiles. Controsands can be used alone or in combonation, layered to create different scapes. Santa Fe is a beautiful gravel that draws inspiration from natural riverbeds and streams. Santa Feâs rich mix of cool grey and earthy hues provides a unique look that is ideal for accent use or biotope aquariums.