RO/DI help

Started up my RO/DI yesterday to fill my top off storage. Came down this morning to a tank that was still not full, and low pressure on my unit (25-30 psi) pressure guage is after the RO membrane and before the DI resin and typically runs about 50 psi. Tried to flush, and that doesn't even seem to be moving much water across the membane. Checked the incoming water and its 60+ psi, water after the first 3 stages is also around 60 psi.


RO membrane is probably just a little over a year old, and TDS after it is 4ppm even at the low pressures. I don't think that is the issue. Flow restrictor was replaced with the membrane. Do these go bad? I opened it up, but didn't see anything out of the ordinary. I thought I had another one laying around here, but in all my piles of junk I can't seem to find it LOL.


What does everyone think I need to look at first?

 

That was a thought I had as well so I did bypass that and the results were the same.

 

I completely took off the asov.
I also pulled the membrane out and let it run for a few minutes without it. I got no pressure on the gauge which I believe would be correct as there would be no back pressure from the membrane. I really am starting to think its just my flow restrictor not pulling its duties. Its letting waste water pass by the membrane too freely. Does this sound reasonable?
I guess the good thing about it is that shouldn't cause any problems with the RO membrane. It does however appear to have used up a good chunk of my DI resin already.

 

I really didn't pay too much attention the the DI before this morning, so it may not have lost much. I just changed it several weeks ago and today noticed that most of it was dark already. I don't know what it was looking like the last couple times I made water. Its still outputting 0 TDS, so that may not be an issue as I said.

I don't know the ratio, bit it is nowhere near 4:1 at this point. Its a solid flow out the waste end, and not much more than a fast, steady drip out the clean end. I can usually fill my 35 gallon container in about 8 hours. It was probably closer to 20 hours and only 30 gallons before I shut it off this morning when I noticed the issue. The restrictor does have the built in valve. I tore it apart, and all the seals and everything look good, but I think it still may be the culprit. I think I'll change that out first. Are the ones without valves more reliable. I may go that route since its cheaper and get a couple fitting and make my own flush valve.

 

no different than it has always been.

 

the ball and the handle are not screwed together. The ball turns just fine, and it does restrict the flow to some extent just not much at all. I'm going to order a regular restrictor and seperate bypass and see what happens. Its cheaper than the all in one unit anyway.

 

I *think* I got this figured out. I bought a new flow restrictor and that didn't resolve the issue.
Today I got fed up and started pulling filters and ASOV valves and getting really frustrated because I couldn't narrow it down to one thing. Had the thing apart and back together in different configurations several times. Took all the filters out and the ro membrane, took the ASOV valve out, took the fast flush out and ran the plain in-line restrictor. Pressure was good. Added the RO membrane and tried again. Pressure was good. Put the DI and pre-filters back in. Lost pressure - WTF - So now I have it narrowed down to the first carbon block filter. Took that out and all was well again.
I'm not sure how I was first checking pressures after the prefilters, but obviously I did it incorrectly because that was where the issue lies. And it makes sense too as I had changed out the filters a couple weeks prior. Now how it got clogged so quickly is beyond me. Could be a fluke, could be inferior filters. I don't know, they were BRS filters that I had never used before. I do know that I'm going back to air, water, ice for a replacement. Its their unit, and I have never once had an issue with their filters and have used them several times in this unit as well as my old one.

Moral of the story, and a good one for reefing in general is - When a new problem arises always go back to the last thing you fudged with and unfudge it. And also if you find something that works don't change it.

 

Now I'm losing pressure again. Really thinking these BRS filters are just crap.

 

I just ordered a new filter pack from Air, water, ice. I had always used them in the past without issues, and they are a club sponsor. Discounts I got today on the order almost equaled my membership cost. /DesktopModules/ActiveForums/themes/_default/emoticons/smile.gif