RODI ratio too low and can't get higher

[AZDesertRat]

It would still be wet after only a couple days. It would take weeks or months to dry out if you didn't open the membrane housing.

 

[mcarroll]

The unit would be pretty heavy to move without being drained first...to me that's likely...but @ps2cho did you drain the unit, or move it sealed up and full?

 

[Opus]

AZDesertRat can chime in on this, but if it sat in the yard did it get direct sunlight? I'm wondering if that would harm the membrane?

 

[mcarroll]

On a quick Google search, Filmtek membranes seem to have a max operating temperature of 113ºF.

If there was water in the housing, it may have been a degree or two cooler than if empty.

If it seems possible that the housing may have hit 113º inside, then the membrane is probably toast.

(Direct sun is intense! my outdoor thermometer hits 100ºF+ on cool sunny days all the time.)

I should add that I have no idea what the effect of excessive heat would be....melting? disintegration? No idea....but not good. ;)

 

[AZDesertRat]

The glues that hold membrane windings together are heat sensitive. Unless it sat out in direct summer Sun or had hot water run through it I doubt that is the problem though. Mine has been mounted in my garage in Phoenix with the double door exposed to western Sun for 15 years with no issues. It's only in the last 5 years I added an insulated door and a window AC.

 

[mcarroll]

Mine has been mounted in my garage

Unless your RODI is mounted in the window of the garage, that's indoors....big difference. (Which I know you know....just sayin!) :)

Try mounting an outdoor thermometer in the RODI's space. You're welcome to do this hypothetically. ;) Then take the thermometer to the same space on the outside of the wall from the RODI where it can actually be directly hit by the sun. On a sunny day, note the different peak temperatures inside and outside and what time of day they show up. The one outside will spike over 100º almost as soon as the sun hits it in the morning. Inside, it won't even hit peak until afternoon and the peak will most likely be significantly lower.

It sat for about 2 days in the yard

Seems likely to have received some sun after two days in the yard, but I suppose we'd have to know if it was under a deck or something.

 

[ps2cho]

Spectrapure emailed me back and said that they have been having water issues in their office with Tempe having over 1000 tds at times.

They asked me to send them back my total mL and they would find me a flow restrictor that will get me a better ratio.. I'll start there for sure as if I end up replacing the membrane it needs to be closer to 4:1 anyway.

 

[ps2cho]

Stopped by Spectrapure today and after a quick chat, they were sure based on my flow rates coming out, the RO membrane was the issue.

I picked up the 99% Membrane along with a fresh set of DI's and a new restrictor. Right off the bat its already way better. ALSO -- Its quieter!! Im not getting this flushing noise that it had before. Its completely silent.
I adjusted the waste ratio to 4.1x and I am letting the membrane run for 1hr RO only before I connect the DI cartridge.

It says to run the membrane for about an hour so to purge everything before looking at RO TDS coming out. It was showing 12ppm versus 27ppm this morning. I'm guessing after an hour it'll improve a little more too.