the toms aqualifter clogs with kalk, its not the actual pump that clogs but the line out of the pump. been there and have gone the route your trying. you will have to upgrade your dosing pump. or go with a cheap pump with a faster flow and larger lines yes thats where i ended up ordering threw. but they are out of stock. placed the order just waiting for the item to come in than they will ship it out. i have to say they are awesome when you call. Enrico is a hoot! and very informative.