Black Aquarium Silicone Sealant - 10.2 Fluid oz Cartridge This high modulus component RTV Silicone Sealant forms strong cohesive bonds to glass without the need of primers The bonds are unaffected by continuous immersion in water and, when fully cured, is non-toxic to fish. ASI Aquarium Silicone Sealant is a non-slump sealant and can be applied to vertical surfaces without flowing or sagging. Can be applied to surface temperatures from -18C to +50C (0F to +120F) and after curing, withstands constant operating temperatures from -57C to +233C (-70 F to 450F). Formulated for use with fresh and salt-water aquariums or a Vivarium