Aquarium Pharmaceuticals (API) Nitra-Zorb filtration media is a ready-to-use pouch that can be added to your filter for ammonia, nitrite, and nitrate removal. Nitra-Zorb filtration media is made of natural and synthetic ion-exchange resins that selectively remove toxins from freshwater aquariums. Nitra-Zorb filtration media is completely phosphate-free and can be reused after recharging.

• Size 6. One large filter pouch.
• For freshwater aquariums up to 55 gallons
• Removes ammonia, nitrite & nitrate
• Reduces risk of fish loss
• Great for starting a new aquarium
• Fits most filters