Aquarium silicone tube is a non-toxic, safest, and very strong utility. It is utilized for affixing to air pump socket with air stone, use in water circulation system with various filters, CO₂ & hydroponics, and boasts complete water resistance. Formulated without any chemicals, it's totally harmless to aquatic life, and can securely apply in any aquarium ecosystem, no matter is it fresh water or sea water tank.