Our 100-percent silicone aquarium sealant is easy to apply and waterproof to stop leaks * The high strength silicone creates a permanent seal that will not crack Or shrink and is non-toxic making it perfect for use on all aquariums * For standard aquariums use clear and Black Seal aquariums use Black sealant * Our 100% silicone aquarium sealant is easy to apply and waterproof to stop leaks * Our 100% silicone aquarium sealant is easy to apply and waterproof to stop leaks. * For standard aquariums use clear and Black Seal aquariums use Black sealant. * The high strength silicone creates a permanent seal that will not crack Or shrink and is non-toxic making it perfect for use on all aquariums.