Changed RO Membrane But TDS Is Still High? Common Reasons and Easy Solutions!

Okay, so, I’ve got a bit of a head-scratcher with my RO system and I thought I’d share my experience, see if anyone’s been through the same thing.

So, picture this: my tap water’s TDS is reading around 140, which isn’t terrible, but I want that crisp, clean water, you know? My RO membrane was about a year and a half old, and the TDS out of the RO was creeping up to 12. Not bad, but I figured it was time for a change.

I went ahead and swapped out the old membrane for a new one. Easy peasy, right? I’ve done it before, no big deal. I followed the usual steps, flushed the system, the whole nine yards.

But here’s the kicker: after changing the membrane, the TDS reading went up, not down! It is really odd. It is higher than before. How does that even happen? It’s like the opposite of what’s supposed to happen.

Here’s what I’ve checked so far:

• The membrane is seated properly. I double-checked, even triple-checked. It’s snug as a bug in there. No leaks, nothing.
• The flow restrictor is doing its thing. Water’s moving through the system just fine, no clogs or anything.
• The water pressure is good. I’ve got a booster pump, and it’s humming along nicely, giving me plenty of pressure.

So, what gives? I’m starting to think maybe the new membrane is a dud, it is old, or maybe I messed something up, even though I’m pretty sure I did everything right. I mean it will generally be high when first turning the unit on due to TDS creep across the membrane. But it is still a little bit higher than before.

Anyone else ever run into this? Any ideas what I should check next? I’m about to pull my hair out over here!

Update

Okay, I have run a few tests as some of you suggested. I checked the TDS before and after the membrane. The tap water is still around 140, and the water coming out of the membrane is now higher than before. It is still climbing!

I guess it is possible that I just got a bad membrane. It happens. Or maybe there’s some weird contaminant in my water lines that got stirred up when I changed the membrane? I’m going to try flushing the system a few more times and see if that helps. If not, I might just have to bite the bullet and get another new membrane. Ugh.

Thanks for the input, everyone. I will keep you posted on how things go.