True and not true Boonboy.
Definition is true but different is in stages.
RODI like Zero 5 stage purifies water by passing water through reverse osmosis membrane then deionized resin.
DI units like Crystal purifies water by passing water through the deionised resin.
The lack of the reverse osmosis membrane shortens the lifespan of the resin.
So if standard lifespan of the resin with RO membrane is 2 years, the same resin only lasts 6 mths without the RO membrane.
Nevertheless both serves the same purpose in purifying water.
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