Hydro Logic BIGboy KDF85/Catalytic Carbon Filter (HL22070)Now chloramines, iron, hydrogen sulphide and heavy metals don't stand a chance against Hydro Logic's newest offering in replacement filters for all their water filter units. KDF85 is the most advanced media that one can use when it comes to filtering water along with pre treating water before Reverse Osmosis filters. The KDF85 not only has incredible chlorine and chloramines removal capabilities but it can also be successfully used for those on well