Kent Marine Nitrogen Sponge 3.3 lbs.

Kent Marine Nitrogen Sponge is a granular zeolitic medium that directly adsorbs ammonia in freshwater and fosters anaerobic bacteria growth to reduce nitrate levels in both marine and freshwater aquariums. Use 1 cup for each 20 gallons of aquarium water. Place in large mesh bag or a canister filter, directly in water flow. Shipping weight: 4 lbs.