API Nitra-Zorb Filter MediaAPI Nitra-Zorb is a rechargeable filter pouch of ion-exchange resins that selectively pulls ammonia, nitrite, and nitrate out of freshwater — the full nitrogen-cycle trio. It's genuinely useful in a crisis: a new tank that hasn't cycled, a sudden ammonia or nitrite spike, or stubbornly high nitrate (including nitrate that comes straight out of your tap water). It won't alter pH or hardness and is phosphate-free.A Gentle Word of Caution — not for planted tanks: In a planted aquascape, nitrate (and the nitrogen behind it) is a plant nutrient — stripping it out with Nitra-Zorb can starve your plants of the nitrogen they need to grow. It also removes ammonia your biofilter feeds on, so it can interfere with cycling. Think of it as a fish-only or emergency tool, not something to run continuously in a fertilized planted tank. For planted tanks, water changes and live plants are the better nitrate control.Good to Know: The pouch is reusable — once exhausted, you recharge it by soaking in an aquarium-salt solution, then return it to service. A 7.4 oz pouch treats up to about 55 gallons.How to Use: Rinse, then place in the flow path of your filter after mechanical media. Recharge on the label's schedule (more often when battling a spike), and replace the pouch after about two months.