GrowMax Water 20" Green Coconut Carbon Block Filter - Compatible with HydroLogic TALLBoy - Case of 25This 20 Green Coconut Carbon Block Filter is compatible with the HydroLogic TALLBoy Dechlorinator & Sediment System. In water filtration, coconut carbon is preferred over other forms of carbon due to its greater surface area and higher porosity meaning it has superior absorption capabilities. Our Green Coconut Carbon Block filter removes 99% of impurities and VOCs volatile organic compounds) including chlorine, rust, sediment, and silt. Flow Rate: up