MABOTO 20pcs 18mm Biological Bio Balls Aquarium Fish Nano Tank /Dry Canister Filter Media Black

Features: Great for fish tanks, to promote gas exchange and increase dissolved oxygen levels. Great for tropical fish farms, koi ponds, waste water systems, etc. For use with /dry filters(here is not included), to improve biological filtration. Aiding in the critical gas-exchange process that is needed for successful biological filtration.  Specifications: Color: Black Material: Environmental Quantity: 20pcs Dia: 18mm / 0.7in Package Size: Approx. 13 * 9 * 2cm / 5.12 * 3.54 * 0.79in (L * W * H) Package Weight: 25g / 0.88oz Package List: 20 * Bio Balls

Great for fish tanks, to promote gas exchange and increase dissolved oxygen levels.Great for tropical fish farms, koi ponds, waste water systems, etc.For use with /dry filters(here is not included), to improve biological filtration.Aiding in the critical gas-exchange process that is needed for successful biological filtration.