SUITABLE FOR: Freshwater and saltwater aquariums. GRAIN SIZE: The sand has a very fine grain, 1-2 MM, in a size of 2 KG. ADVICE ON USE: Place an indicative layer of 4 cm on the front and 7 cm on the back, creating a gradient that gives depth to the vision of the pool. NON-TOXIC: Thanks to this natural substrate, you can set up your aquariums in a safe way, the product is colored with natural pigments, it does not release carbonates and this makes it non-toxic to fish, invertebrates and plants. PACKAGE CONTENTS: The package contains aquarium sand specifically selected to recreate a natural seabed.