Dick Boyd's Worlds Famous Chemi-pure - LONGER LIFE - Fish often live three to four times longer than in any other closed system, fresh or marine. - NECESSARY ORGANISMS - Allowed growth with no danger of pollution. - REMOVES OFFENSIVE ODORS - REAL SEA WATER OR ARTIFICIAL - REMOVES TOXIC ELEMENTS - Including Copper & Phenol - IMMEDIATE ACCLIMATION - with ravenous appetite. - QUICKER RESPONSES - Neurological reactions like fishes in natural habitat. - FRESHWATER FISHES - of all species thrive - ESPECIALLY GOOD FOR AFRICAN CICHLIDS & DISCUS - NO WATER CHANGE NECESSARY - for at least 5 years (length of test only) PERHAPS NEVER! - CRYSTAL CLEAR WATER - Always sparkling blue-white water - NO CLEANING - Necessary for health of fish. - CONSTANT pH - Always within the safe range - NO OSMOTIC SHOCK - 90% eliminated - NO ION ANTAGONISM - ECONOMICAL - Replacement only every four to six months makes initial cost very low - eliminates expensive water changes - fewer losses. Chemi Pure is unlike any mechanical or chemical filtration material you have used before. Whether you are a fresh water or salt water enthusiast, it is something you will have to use, see, and test for yourself in order to believe the results. Chemi Pure comes already packed in pure polyester filter bags in sealed plastic bottles which are termed one unit each also available in 1/2 units of 5oz. One unit is recommended for up to 40 gallons of water and which remains completely active for 4 to 6 months with no regeneration or cleaning required. We recommend that, in cases of heavy bio load, that each unit of Chemi Pure be replaced within 3 to 4 month period. Each bag of Chemi Pure is simply removed from the plastic bottle and installed directly in your filter. It is pre moistened and should be rinsed prior to use.