Is there a difference?

[Rob6311]

Ok so I went to my LFS to but RODI water and they kept just calling it RO water, my question is, is there such a thing as just RO water that's different then RODI water? Or is it the same thing?

 

[Jritter02]

RODI is one step farther then RO. RO is just reverse osmosis...the DI is dionized water on top of it. It's a other filter on the RO system.

 

[James77]

The DI will grab anything the RO misses. Depending on your tap water, what comes out of the membrane can still have a decent amount of TDS, as a RO membrane only pulls out a certain percent(its efficiency).

For example....if your tap TDS is 300 and your RO membrane has a 97% rejection.....you will still be left with 9 TDS. Far from the end of the world, but DI is cheap enough to run fro such a small amount of TDS.

Some will just refer to RODI water as RO water though......