Aqua Tech 20-40 & 30-60 Gallon Power Filters, 6 Pack

Aqua Tech Ez Change Replacement Filter Cartridge 6 Pack.  4.50 x 6.00 x 6.75 inches. Three Stage filtration for healthier fish. Change filters monthly for crystal clear water. 
Stage 1: the filter cartridge floss screens out dirt and debris.
Stage 2: Activated Carbon inside filter cartridge removed oders, discolorations and impurities.
Stage 3: The Bio-Tech biological grid that comes with your power filter, never needs to be replaced. This ensure eliminatin of toxic ammonia and nitrate. This filter also has a unique design that it will not clog up.