RO membrane safe?

[Jonreefer]

I bought a 75GPD membrane about 2years ago and was using it to make water for my detailing chemicals. I probably only put about 50gal or so through the unit. I stopped using it for about a year and a half and the unit stayed wet the entire time in the housing.
I just started using it again getting ready to start up a tank. I pulled all the filters and membrane out of my RO unit and gave it a bleach flush to kill anything in the canisters. I put all new pre filters in and put the membrane back in. I have a TDS of about 200-300 and the membrane is spitting out around 2-3TDS so figure its working fine but is there any chance of maybe a bacteria or mold in the membrane that could make the filter unsafe to use and just replace it. Or am i worrying to much?

 

[Randy Holmes-Farley Verified Community Expert]

Assuming you are not drinking the effluent water, it will be fine.

 

[Buckeye Hydro Verified Sponsor]

is there any chance of maybe a bacteria or mold in the membrane that could make the filter unsafe to use and just replace it.

There sure is. It's likely. But, considering how you're using the water, its not going to be an issue for you. You generally want to check TWO things re membrane performance in your situation: Rejection, and flux.

Your rejection is fine, given the number you provide above.

Check the production of your membrane (ml/min is often the most convenient unit here, and then mathematically covert that to gal/day), and then using this calculator, check how that compares to what you should be producing. A membrane that is biofouled may produce significantly less volume of pure water than it should.

Heed Randy's comment about not drinking the water from that membrane!

Russ

 

[Jonreefer]

well I ended up replacing it with a new membrane anyway. because I tested it a few days later and noticed the TDS flew up to 20 so figure it failed.