water purification???

[BCOrchidGuy]

DI is the polishing phase on an RODI system it removes pretty much what the RO unit doesn't. My personal opinion is that RODI is used because the DI would need replacing or recharging after just a little water passed through it in a large number of areas PLUS people would still need a sediment prefilter. Our water here is very very soft meaning not a lot of dissolved carbonates etc in it so to answer your question, Yes DI is an excellent way to go.
If you check around you'll find instructions on how to recharge your DI filter so you can keep using the resins again. I have used just DI for years and find I get well over 1000 gallons before the resins need attention.

Doug