This is the most common “mid-level” setup I see. You throw a reverse osmosis (RO) unit in front of a DI system. The RO removes 95% of the bad stuff, and the DI just has to polish the leftovers. Brilliant in theory. In practice? The RO membranes hate chlorine (need carbon pre-filters) and the DI resin lasts much longer.
Honestly, for 80% of manufacturing (food, cosmetics, general rinsing), this is your sweet spot. Not too expensive, not too fragile. Just remember to swap the carbon filter on schedule, or you’ll be Googling “why does my DI water taste like a swimming pool.”
