RO/DI problems

[capt85]

Well i finally ordered new filters for my RODI and i feel as though i have lost ground. I replaced all 3 prefilters and 2 chambers of DI. After 15 gallons my DI is shot and my TDS is creeping up. Luckily I bought 2 refills but i am not going to replace them until i can figure out what the problem is.

My in reading after 2 hours of flushing is still 85 TDS.

Does this sound as if my membrane is bad?

Thanks

 

[skinz78]

So you didn't replace your membraine?

 

[capt85]

No i did not, I was under the impression that membranes lasted much longer than the DI and prefilters.

 

[dccordell]

Normally they do last longer, but that depends on your tap water.

To start troubleshooting any RO/DI, you need TDS levels of 1) tap water going in, 2) product water from RO (before DI), 3) TDS after DI resin. Since your DI resin is apparently shot, the most important numbers now are tap water and RO water TDS. If the RO isn't cleaning the water enough, the DI resin will exhaust quickly trying to compensate.

Also, what was your TDS levels out of your DI before you changed the filters? Was it high then too?