Look into the hazardous chemicals required and the amount of water it takes to recharge the resins. Also remember you will probably never be able to recharge the resins to more than maybe 80-90% strength as its not easy to do at home, when its manufactured they use heat and other processes. I would pass unless and only if your incoming tap water has a TDS of less than 50 ppm. DI resin without pretreatment (RO membrane which does 90-98% of the work) does not last long and there are things DI will not remove just as there are things a softener, carbon or RO do not remove, it really takes all four processes to work effectively. There is no substitute for RO/DI.