Hypersorb - 250 mLHyperSorb is a synthetic adsorbent that outperforms all other blended synthetic media. It has exceptional organic removal capacity, stabilizes the ionic balance, and helps to control ammonia, nitrite, and nitrate. Exhaustion is indicated by discoloration (yellow to dark brown). It can be regenerated easily with household bleach.Each 250 mL treats up to 75 gallons.