D-IONIZR2SET MKIID IONIZR2 WATER FILTRATION SYSTEM 3 STAGE FILTER SET UP The D IONIZR2 has a 3 stage filter set up. The first filter is a composite carbon filter which is designed to remove the hardness levels of your water. This also adds an extreme benefit to the D IONIZR filter as the water flowing through it will be much cleaner and prolonging the life span of your cartridges. We have seen a 20% increase of your DI cartridge with this set up. The 2nd & 3rd filters