RO/DI Membrane Seals Can Fail & Alow TDS To Go Up

[bbyatv]

I just ordered a new membrane for my RO/DI unit from AirWaterIce. My TDS coming out of the unit prior to going into the DI media had gone way up. I figured I need a new membrane even though it was only 1.5 years old. These normally last at least 3 years. I went ahead and ordered one. The new membrane will be here Thursday so I figured I would read up on how to replace it. While I was reading this site:

 

http://www.melevsreef.com/rodi_membrane_change.html

 

I noticed towards the end of the instructions that the author mentioned that the seals on his membrane had slipped a few inches down the unit as a result of the high pressure. I started thinking maybe the seals had slid completely off the membrane in my unit.

 

I pulled the membrane out and just as I suspected. The outside seal had come completely off. I cleaned up the inside to the tube, restored and re-taped the outside seal and re-installed the mebrane. I started the RO/DI unit up again, let it run for a few minutes, and wa-la, my TDS was back down where it belonged before heading into the DI media for polishing.

 

Lesson learned: If TDS on your RO/DI suddenly goes up, check the seal on the membrane.

 

Bruce

[DaveS]

Hey Bruce,

 

Good catch. Got any pictures?

[Coral Hind]

What is your water pressure? I had one fail about a year ago. Just another reason to have an inline TDS meter.

[Origami]

Good info, Bruce! Thanks.

[bbyatv]

No. I did not take any. If you visit the web site in the original post, you can see some pics of the seal in the wrong and right loactions.

 

Bruce

 

Hey Bruce,

 

Good catch. Got any pictures?