Keep your aquarium leak-proof with the Aqueon Aquarium Silicone Sealant. Formulated with 100% silicone, it forms a clear waterproof seal to stop leaks, and does not crack or shrink when applied. It’s actually the same high-strength silicone that’s used to make new aquariums so it’s a long-lasting, professional-grade bond you can trust. And since it’s non-toxic, it won’t harm plants or fish and works in both freshwater and marine aquariums. Plus, the formula is proudly made in the USA.