RO/do help needed

[Reefpro]

so just replaced the membrane, (99.8%) sediment, filter, carbon block, chlorimine block, HC DI resin and the Uktra DI (final polish) all of which came from Specrapure. Final TDS is 0. But the problem is I have very low production rate compared to replacing everything. Everything replaced is identical to what was in there to begin with. I use a booster pump and run at about 75 psi my temp in WA state is in the 90's.

What could cause my very slow production rate (less than 30 gallons per day) the membrane is rated at 90 GPD. Production was on par before filter swap just high TDS.

 

[shiftline]

Generally it's all based on the pressure. Are you sure your bosster pump is working 100%. Do you have a one of the membrane housings with the pressure gauge?

I know it's supposed to be used with cold water not hot... that may be part of it if your running 90 degree water though it

 

[Reefpro]

Generally it's all based on the pressure. Are you sure your bosster pump is working 100%. Do you have a one of the membrane housings with the pressure gauge?

I know it's supposed to be used with cold water not hot... that may be part of it if your running 90 degree water though it

It has pressure gauge before membrane reads 77 and gauge after membrane reads 76 psi temp here is i90 and is hooked to cold water in basement. No problem till I switched membrane, pre filters and DI RESIN.

 

[prsnlty]

so just replaced the membrane, (99.8%) sediment, filter, carbon block, chlorimine block, HC DI resin and the Uktra DI (final polish) all of which came from Specrapure. Final TDS is 0. But the problem is I have very low production rate compared to replacing everything. Everything replaced is identical to what was in there to begin with. I use a booster pump and run at about 75 psi my temp in WA state is in the 90's.

What could cause my very slow production rate (less than 30 gallons per day) the membrane is rated at 90 GPD. Production was on par before filter swap just high TDS.

Maybe you need to replace the flow restrictor. This should be done with each membrane replacement.

 

[Reefpro]

Maybe you need to replace the flow restrictor. This should be done with each membrane replacement.

I was not aware of this and guys at specrapure said nothing about this

 

[prsnlty]

I was not aware of this and guys at specrapure said nothing about this

It always seems to get overlooked and why I mentioned it

 

[Water Dog]

Also, when you replaced the prefilters, did you flush each prefilter downstream bypassing the RO membrane?

Empty out the prefilter canisters and unhook the RO membrane. Install the sediment filter and flush it for 5 minutes. Then install the carbon block and rinse for 5 minutes. Then attach the membrane line. That way the prerinsing won't foul the membrane.

 

[Reefpro]

What is the fix now or ambi just screwed?

 

[Reefpro]

@AZDesertRat

 

[Water Dog]

Not sure we've isolated the problem yet. Have you tried a new flow restrictor yet? If you didn't preflush the prefilters. Try to flush the membrane if you have a flush valve.

 

[KStatefan]

What is the ratio of product to waste?

You can flush the membrane by removing the flow restrictor if you do not have a flush valve

 

[Reefpro]

I have a flow restrictor and i have a flush valve one thingvive noticed is the flysh vslve only work when there is no pressure on the solenoid from booster pump (ie: actively making water) a d when i open flush valve some water still goes into holding tank while flushing

 

[Opus]

In all my years of reading on RO units, I've never read to replace the flow restrictor after changing the membrane unless you change to a different GPD membrane. I've had the same one for well over 10 years. Also, flushing really doesn't work on home units. As suggested, do a waste to good water test to see where you are at. Warm water actually will increase production. That is why your production goes down in the winter months. You could also up the pressure. I believe azdesertrat runs his around 100psi and he is the guru. Do you know the GPD you were getting before you changed the filters? Personally, the first thing I would do is reseat the RO membrane just to make sure it is in correctly. If it is then I would probably call/email Spectrapure and get their advice. Could be just a bad RO membrane.

 

[Reefpro]

In all my years of reading on RO units, I've never read to replace the flow restrictor after changing the membrane unless you change to a different GPD membrane. I've had the same one for well over 10 years. Also, flushing really doesn't work on home units. As suggested, do a waste to good water test to see where you are at. Warm water actually will increase production. That is why your production goes down in the winter months. You could also up the pressure. I believe azdesertrat runs his around 100psi and he is the guru. Do you know the GPD you were getting before you changed the filters? Personally, the first thing I would do is reseat the RO membrane just to make sure it is in correctly. If it is then I would probably call/email Spectrapure and get their advice. Could be just a bad RO membrane.

Great sdvice. Sent azdesert a Pm hoping to get a reply soon

 

[Reefpro]

Just talked to spectrapure and said that not changing the fliw restrictor will not cause this. Said it is likely the di resin in one of the two is packed to tight. Has me trouble shooting it now

 

[Reefpro]

After several test they said i got a bad membrane cause the rejection rate is 12:1. So sending out nee membrane

 

[Water Dog]

Nice!

 

[Reefpro]

In talking with Scott at spectrapure he said no rinsing of prefilters is necessary and very srldomly dobyou need to change fliw restrictor he did say that DI resin gets packed to tight snd restricts flow of water

 

[Buckeye Hydro Verified Sponsor]

Its not really possible to pack standard mixed bed DI resin too tightly.

 

[Buckeye Hydro Verified Sponsor]

the rejection rate is 12:1.

Just to avoid confusion...

REJECTION is the percent of feedwater TDS that does not make it through to the RO water

RECOVERY is the percent of the feedwater flow that ends up as permeate ("RO water"). So if you had 1 part permeate to 12 parts concentrate, you'd have 12+1=13 parts feedwater. 1/13 = 0.076, or about 8% recovery. At the often quoted 4 to 1 ratio, you'd have a (1/5=) 20% recovery.

Russ