This Boyd Chemi-Pure Elite Filter Media helps keep your underwater buddies’ home in tip-top shape. This all-in-one filter media is suitable for all water types and helps absorb chemicals and generate ions to encourage constant pH levels. Chemi-Pure Elite now contains ferric oxide， which helps remove phosphates and slime to promote healthier living conditions for your coral and your finned friends. It comes in a convenient pure polyester bag and can stay active for four to six months without water changes!