Eating Up RO Membranes

[Woodyman]

Good information. My RODI does an automatic flush but not long enough to get to cool water. I will try running a faucet in the same line prior to starting to fill the ATO reservoir. Appreciate the advise.
Sorry, OP, but I cannot think of anything else that you have not tried. Perhaps try ordering the membrane from another supplier? Is there a chance that the ones they sell you are just old? Also consider getting your water tested independently.

77 degrees is typically considered ideal water temp for the RO membranes, higher and you can technically produce more RO per gallon, but going to far will prematurely age your filters, and going way above typically 110+ will start melting the film within the RO membrane. When your temperature is lower you will produce less RO per gallon but your filters will last longer.

Most of the ratings for RO membranes are based on a water temp of 76-78 degrees (F).

 

[flyfisher2]

Have you tested for chlorine/chloramines post sediment and carbon? If not just based off of what I've read so far I would start with that and diagnose based on that result.

I contacted my local water supply the last time I changed my membrane, three months ago and the tech told me that chlorine is all they use. I have not tested

 

[flyfisher2]

Try just reseating the membrane. Pull it out all the way then make sure you give it a firm push into place when seating.

Thanks and I've done that repeatedly with the last three membranes. Even tried tapping them in

 

[Woodyman]

I contacted my local water supply the last time I changed my membrane, three months ago and the tech told me that chlorine is all they use. I have not tested

Hopefully they are correct, but it doesn't hurt to check your local water report.

I would recommend either a chlorine test kit or even some test strips just as a quick check and verify your water post sediment and carbon is not registering any chlorine.

 

[flyfisher2]

77 degrees is typically considered ideal water temp for the RO membranes, higher and you can technically produce more RO per gallon, but going to far will prematurely age your filters, and going way above typically 110+ will start melting the film within the RO membrane. When your temperature is lower you will produce less RO per gallon but your filters will last longer.

Most of the ratings for RO membranes are based on a water temp of 76-78 degrees (F).

This is Central Florida. Outside temp is in the 90's right now. Sounds like I need to bring this whole setup into the house.

 

[flyfisher2]

Hopefully they are correct, but it doesn't hurt to check your local water report.

I would recommend either a chlorine test kit or even some test strips just as a quick check and verify your water post sediment and carbon is not registering any chlorine.

I did that as well as they send it out yearly. The purify with chlorine. No mention of chloramines

 

[Woodyman]

This is Central Florida. Outside temp is in the 90's right now. Sounds like I need to bring this whole setup into the house.

Yep if your running the unit outside you are more thank likely killing the carbon way faster than your currently replacing it and you are also degrading that RO membrane faster. The high temp and possible chlorine would explain the rapid decline in your membrane efficiency and failure.

 

[flyfisher2]

Good information. My RODI does an automatic flush but not long enough to get to cool water. I will try running a faucet in the same line prior to starting to fill the ATO reservoir. Appreciate the advise.
Sorry, OP, but I cannot think of anything else that you have not tried. Perhaps try ordering the membrane from another supplier? Is there a chance that the ones they sell you are just old? Also consider getting your water tested independently.

I've ordered from BRS and Amazon. Three membranes all bad? Will try to test for chlorine. I sent my water in for testing but it was post RO/DI with my ICP test

 

[Woodyman]

I did that as well as they send it out yearly. The purify with chlorine. No mention of chloramines

I've ordered from BRS and Amazon. Three membranes all bad? Will try to test for chlorine. I sent my water in for testing but it was post RO/DI with my ICP test

I wouldn't assume you got 3 bad membranes in a row, that would be some amazing bad luck. Based of everything so far perform a check of the chlorine post carbon and ideally flush the line until a stable temp is reached prior to sending through the unit, and better yet move the unit inside and still purge the line prior to production.

 

[flyfisher2]

Yep if your running the unit outside you are more thank likely killing the carbon way faster than your currently replacing it and you are also degrading that RO membrane faster. The high temp and possible chlorine would explain the rapid decline in your membrane efficiency and failure

never bought chlorine test kit before. Recommendations?

 

[Woodyman]

I've ordered from BRS and Amazon. Three membranes all bad? Will try to test for chlorine. I sent my water in for testing but it was post RO/DI with my ICP test

You should be able to find them relatively fast and cheap, any pool store should have the strips or you could even pickup a dedicated chlorine test kit for more accuracy.

 

[flyfisher2]

pool strips? I have those. Hang on

 

[Woodyman]

never bought chlorine test kit before. Recommendations?

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[Woodyman]

Pool strips arent the most accurate thing (think API test kits) but they can give you a ballpark.

 

[Woodyman]

I would recommend the Spectrapure kit, since it registers in the low range and they have been pretty accurate in my experience when cross checking.

 

[flyfisher2]

Free chlorine 0
Total Chlorine 0
at the faucet and post the carbon blocks
And the strips are good. Used them with shock earlier this week

 

[flyfisher2]

Okay, so buy a test kit

 

[Woodyman]

Free chlorine 0
Total Chlorine 0
at the faucet and post the carbon blocks
And the strips are good. Used them with shock earlier this week

That's good at least they aren't reading off the charts. What is the test range on the strips? You could still have chlorine going through, but the strips aren't precise enough to pickup the low ranges.

If your carbon is good the next thing would be to check your housings, and o rings.

 

[Woodyman]

Okay, so buy a test kit

If you want to go with best practice I would, especially with blowing through RO membranes since that isn't normal.

However it could still be a bad seal or just the temperature your running the unit at.

 

[flyfisher2]

Thanks very much Woodyman and all others. I've already ordered another canister and I'll order the chlorine test kit. It seems I need to bring my RO/DI station indoors.