Pro Ban T Citric Acid (6 - 4 lbs. Bottles) CASE Includes six 4.0 lb. bottles - 1 full case Will remove iron, tannins and other build-up from water softeners AND backwashing filters Increases capacity of the softener unit and backwashing filter Effectively lowers the pH of your water and removes hard water deposits on household items Non-toxic, non-corrosive, and non-hazardous. Safely use on many surfaces.