Spectrastone Blue Jean Aquarium Gravel for Freshwater Aquariums, 25-Pound Bag Go to amazon.com Related posts Top 7 aquarium gravel blue FeatureWill not affect PHSafe for use in freshwater aquariumsNon-Toxic coating DescriptionBlue jean blend aquarium gravel for freshwater aquariums. Will not affect PH. Safe for use in freshwater aquariums.