After our recent posting about commercial reverse osmosis units we expected to receive inquiries about them, but we NEVER expected for so many of you to ask the same question: “What do the replacement RO membranes cost?”

Dow Low Energy Replacement RO Membrane
Low Energy Replacement RO Membrane
Up to 2,400 Gallons per Day

Honestly, we had not pondered that question… until now. Though we checked only one site, it appears as though one may want to do their homework before investing in a commercial reverse osmosis water filter if pinching pennies matters because the RO membranes in the 4,000 gallons per day unit we brought to everyone’s attention uses 4″x40″ filters that cost no less than $290 apiece on the various sites we checked.

We suppose, however, that anyone willing and ready to drop around $5,000 on a high volume water filtration system probably expects to spend a few bucks on the unit’s replacement RO membranes

Thankfully, though, replacement reverse osmosis membrane prices for point-of-use systems for households, small businesses, etc. still cost in the range of $100 or so.

Now that we’ve done a little research, we can definitely say that anyone considering purchasing a reverse osmosis unit should make sure the unit they want to purchase uses a universal size of ro membrane — else face really high replacement costs and/or the risk of not being able to find a replacement at all!