Question about RO membrane
 

I bought a BWI SR-Elite 100gpd back in 2011 and noticed the TDS is starting to creep up. I guess the membraine is on its way out as I just changed all the filters and its sill higher than I'd like. My question is, as it is a 1:1 unit do I need to order a special membrane or is the unit itself what engineers the 1:1 ratio of good to bad? I found the original thread advertising it but BWI never really did say what the membranes were.

http://www.canreef.com/vbulletin/sho...light=1%3A1+ro

Any 100GPD membrane should work, I think the limiter in the waste water line is what improves the ratio to 1:1.

Standard 100GPD membrane, I have the same unit and recall checking what kind of membrane was in it. I'm still on the original membrane but same as you TDS creeping up.

Try flushing out the membrane by removing the Cartrage unit and hooking it up backwards. I couldn't believe the crap that came out of mine and it started working like new again.

Yup, did the same, pure sludge came out :)

right, I was thinking you had one of these and I'm glad you posted :)

LOL, yes Brad was telling me about this however he neglected to mention how to do it :razz:

thanks for all the quick replies guys! Much appreciated :biggrin:

Think about installing a flush as well, keeps the membrane cleaner longer.

http://www.reefsupplies.ca/online-st...ectrapure.html

I think it might have one, where the valve is on that model, there is a little black box that has a cord that plugs into the wall. I guess its an auto flush? It turns on quite often.

Yeah, probably is, if it's working then you shouldn't get much buildup. Depends on your source water though, what's your source TDS?

source is usually between 13 and 20. I haven't had the auto-flush plugged in in awhile so it would have helped to have that plugged in (cord wasn't long enough) but its had a pretty good run of 3 years. I need to change the DI (on order) before I can confirm that I need a new membrane but it seems likely that its the membrane just based on time alone.

Curious, what is the output? Anything to really worry about?

Wow that's a great source! I thought 45 at my house was good haha

It was 9 yesterday. Today its back to zero. I think its screwing with me. The tank is doing well so I think I wont worry about it too much.

That sounds sketchy. I'd measure a few more times and see if you can get a consistent reading.
Mine is probably not 0 anymore, but close enough.

Yeah it was zero again last night. I don't even know if I have the TDS meter hooked up right. I cant' remember where I got it but it had incredibly terrible instructions, they didn't translate well or something. I'll use my handheld one today when I get home. I'm wondering if the 9 reading was when I first turned on the system or something? Who knows. I have zero luck with technology it seems :razz:

Can you take any to work to test?

all our TDS meters at work are inline I think. I might have to pursue that one