Need Reverse Osmosis Help

[kdog_x]

So I purchased a 5 stage R.O. system, out of the box everything worked great. I had a couple great brews and then I figured I wouldn't use it for a couple months so I disassembled everything and dried it out. I reassembled last week and that's when I learned that the membranes need to be kept wet... doh. Nothing out of the feed line and restricted flow out of the waste line.

So I purchased a new R.O. membrane, and I just got to installing it. For some reason the water is just running straight through. I've checked and double checked and I don't know what I did wrong. I posted a video of the setup below. If anyone has any suggestions I would be extremely greatful!!

 

[Amadeo38]

Quick clarification - were you just running the water in and out of the RO membrane without the other filters first? Not totally sure, but maybe there’s supposed to be less pressure going through the membrane by the time it gets pushed through the first two stages (and then I’d imagine it goes through a final polishing carbon filter last?).

Just spitballing here, but are you positive the fast flowing one isn’t the wastewater and the slower flowing one is the filtered water? That would be my guess, but IDK. Just trying to spur some thoughts here.

 

[mabrungard]

It appears that the membrane was inserted into the housing correctly, so the high flow from the product line is odd. Who is the membrane manufacturer?

There is often a period during startup when the membrane doesn’t perform well. It takes hours for the membrane to hydrate and operate correctly. But it doesn’t usually flow freely. Are you sure the o-ring on the center post is intact and sealing? A bit of silicone grease helps assure a seal.

If the unit hasn’t started to flow slowly from the product line after a day or two of hydration, the membrane may be defective and have ruptured. Do you happen to know how high your water pressure is? If it’s higher than about 100 psi, it may have ruptured the membrane. This is especially true since the product line was open to the atmosphere (zero back-pressure) and the hydraulic gradient is high.

 

[kdog_x]

I ended up getting the issue resolved, there was a hairline crack in the 'cup' that the o-ring section of the membrane slides into. So the water was flowing right around the membrane. Ended up having to order a new housing.