Cryptic problem: RO membranes clog up. Please help

[rajdude]

Hello everyone,

I have a very interesting problem related to my RO filter. It has been going on for almost a year. Lots of troubleshooting has already gone into it last year. Talked to multiple vendors, tried different proposed solutions. But the problem keeps coming back.

Problem:

Any new membrane I install drops its water production to half after a month. After a few months the production drops to a trickle. I have measured water production carefully.
Screenshot below:

Proposed solutions that I have tried:

1. Changing RO membrane to a different brand (started with Pentair GRO 1:1, now using DOW Filmtech)
2. Adding a second RO membrane (BRS kit)
3. Adding a second carbon block canister
4. Replacing carbon and sediment block filters

Observations / notes / details:

System setup:​

inlet> Tee to TDS sensor > sediment> carbon> carbon>Tee to pressure gauge> membrane 1 (and membrane 2), Tee to TDS sensor > Tee split to >​

one way valve > DI canister > Tee to TDS sensor > drum > pump to aquarium​

one way valve > remineralization block for drinking water > drum > pump to kitchen water faucet + fridge​

I do have a ASO valve​

​

​

Inlet TDS 175​

post membrane TDS around 4-7​

post DI 0 TDS​

​

Chlorine after the carbon blocks stays very low. Right now it is at 0.02, measured by a Hanna. Carbon blocks were replaced 10 months ago.​

​

Our city uses Chloramines in summer​

​

Summer or winter, does not matter, same problem happens – membrane clogs up.​

​

Water pressure as measured on a gauge installed after carbon blocks = 55 to 70 psi, and that stays pretty much the same, unless someone else us in the house opens water faucet (drops 10 psi)​

​

Adding dual membrane kit does nothing. Almost same rate of clogging happens.​

​

I do not have an auto-flush system. I do flush manually.​

​

I make around 30 gallons of RO water every 2 days. (split into fish tank water changes and drinking water also)​

​

55 gallon brute drum for fish water​

​

10 gallon brute drum for drinking water​

What do you think I should try next?

Thanks for your time and advice



BTW I also posted some stuff in another thread here, but time has passed, so I thought it is probably best to start a new thread of my own...

https://www.reef2reef.com/threads/eating-up-ro-membranes.843152/post-9319924

 

[KStatefan]

Have you talked to Russ @Buckeye Hydro

 

[LeftyReefer]

What sediment filters are you using? .5 micron or 30 micron?

Might try some better sediment and carbon blocks with lower micron ratings.... might catch more of whatever is clogging your membranes??

if you aren't already, try a .35 or .5 micron sediment filter and/or a .5 or 1 micron carbon block.

if your water has a lot of sediment in it, you might want to go ahead and add another sediment filter to your setup too. It can't hurt. prefilters are a lot cheaper to replace annually than membranes.

Water temp also can affect RODI output... lower incoming water temp lowers production... so if you are in a location like I am that gets cold during the winter months, I experience a significant reduction in my RODI production during the winter months when my incoming water is 15-20 degrees colder than it is during the summer months. Your chart seemed to show your production going down in OCT and NOV and bottomed out in FEB. sort of coincides with falling temps in fall/winter. Those are cold/winter months here and my RODI production rate goes down in those months too.

 

[HuduVudu]

Hello everyone,

I have a very interesting problem related to my RO filter. It has been going on for almost a year. Lots of troubleshooting has already gone into it last year. Talked to multiple vendors, tried different proposed solutions. But the problem keeps coming back.

Problem:

Any new membrane I install drops its water production to half after a month. After a few months the production drops to a trickle. I have measured water production carefully.
Screenshot below:

Proposed solutions that I have tried:

1. Changing RO membrane to a different brand (started with Pentair GRO 1:1, now using DOW Filmtech)
2. Adding a second RO membrane (BRS kit)
3. Adding a second carbon block canister
4. Replacing carbon and sediment block filters

Observations / notes / details:

System setup:​

inlet> Tee to TDS sensor > sediment> carbon> carbon>Tee to pressure gauge> membrane 1 (and membrane 2), Tee to TDS sensor > Tee split to >​

one way valve > DI canister > Tee to TDS sensor > drum > pump to aquarium​

one way valve > remineralization block for drinking water > drum > pump to kitchen water faucet + fridge​

I do have a ASO valve​

​

​

Inlet TDS 175​

post membrane TDS around 4-7​

post DI 0 TDS​

​

Chlorine after the carbon blocks stays very low. Right now it is at 0.02, measured by a Hanna. Carbon blocks were replaced 10 months ago.​

​

Our city uses Chloramines in summer​

​

Summer or winter, does not matter, same problem happens – membrane clogs up.​

​

Water pressure as measured on a gauge installed after carbon blocks = 55 to 70 psi, and that stays pretty much the same, unless someone else us in the house opens water faucet (drops 10 psi)​

​

Adding dual membrane kit does nothing. Almost same rate of clogging happens.​

​

I do not have an auto-flush system. I do flush manually.​

​

I make around 30 gallons of RO water every 2 days. (split into fish tank water changes and drinking water also)​

​

55 gallon brute drum for fish water​

​

10 gallon brute drum for drinking water​

What do you think I should try next?

Thanks for your time and advice



BTW I also posted some stuff in another thread here, but time has passed, so I thought it is probably best to start a new thread of my own...

https://www.reef2reef.com/threads/eating-up-ro-membranes.843152/post-9319924

Are you making water continously?

 

[A_Blind_Reefer]

I second needing to know what micron sediment filter you’re running, it’s pretty significant in relation to your problem. You don’t mention the sediment filter being clean or dirty?

Also, when you say you flush manually…. What does that mean? Before, after, during making water?

where is the unit mounted? is it exposed to sunlight?

edit.. are you using float valves in the brute cans?

 

[rajdude]

Have you talked to Russ @Buckeye Hydro

No I have not talked to him yet.

I have talked to Frank from Pure Water Products (that is where I bought the system first, then added stuff to it later from various places)

Also have talked in detail with customer support guys at BRS and SpectraPure.

 

[rajdude]

What sediment filters are you using? .5 micron or 30 micron?

Might try some better sediment and carbon blocks with lower micron ratings.... might catch more of whatever is clogging your membranes??

if you aren't already, try a .35 or .5 micron sediment filter and/or a .5 or 1 micron carbon block.

if your water has a lot of sediment in it, you might want to go ahead and add another sediment filter to your setup too. It can't hurt. prefilters are a lot cheaper to replace annually than membranes.

Water temp also can affect RODI output... lower incoming water temp lowers production... so if you are in a location like I am that gets cold during the winter months, I experience a significant reduction in my RODI production during the winter months when my incoming water is 15-20 degrees colder than it is during the summer months. Your chart seemed to show your production going down in OCT and NOV and bottomed out in FEB. sort of coincides with falling temps in fall/winter. Those are cold/winter months here and my RODI production rate goes down in those months too.

I am using this from BRS

1 x 2.5" x 10" - 1 Micron Premium ROsave.Z Sediment Filter - GE Water Technologies
2 x BRS Universal Carbon Block Filter - 1 Micron

I am on city water in Fairfax, VA. I am not sure if we have a lot of sediment in our tap water. TDS of straight tap water measures 179 right now.

Is 1 micron not good? I am not that much experienced with RO filtration, started this system just 1 year back


You are correct about water temps. But look at my table above. Brand new membranes, in not so cold months , September to October is not too cold here ....the output reduced to half in around one month!

OK even if we think temps did it...what about now?
I just replaced the membrane and the same clogging happened, but yeah this time in 2 months time.

 

[rajdude]

Are you making water continously?

No.
I saw that video from BRS, where they talk about carbon blocks needing "rest"
Usually when the membranes are new, the system runs for around 4-5 hours and then rests for a day.

 

[rajdude]

I second needing to know what micron sediment filter you’re running, it’s pretty significant in relation to your problem. You don’t mention the sediment filter being clean or dirty?

Also, when you say you flush manually…. What does that mean? Before, after, during making water?

where is the unit mounted? is it exposed to sunlight?

edit.. are you using float valves in the brute cans?

1 micron

The last time I looked at the sediment filter, it did not look dirty....but yeah, I know looks can be decieving there I thought a pressure drop would tell me that the sediment filter is blocked.
No pressure drop happens.

I flush manually before and after making water. Usually for 15-20 seconds. I am starting to suspect it needs more flush, or more pressure....IDK :-(

Unit is mounted in the mechanical room in our house's basement. It is a finished, air conditioned basement.

Yes, both Brute cans have float valves. They are there to prevent an overflow just in case I forgot to turn off the RO system (which has happened) LoL. Are the float valves causing some problem? Usually they do not activate.

 

[A_Blind_Reefer]

Most suggest flushing for a couple minutes, not seconds. An auto flush flushes for 15-20 seconds at start, every hour, and when finished. I would definitely start by flushing a bit more. If the 1 micron sediment isn’t getting clogged then it’s most likely mineral deposits in the membrane or just a loss of pressure. Does this happen if you take the drinking water portion off line, and vice versa? Do you manually close and open valves to direct where the water goes or does it flow to both brutes at the same time?

 

[Spare time]

Most suggest flushing for a couple minutes, not seconds. An auto flush flushes for 15-20 seconds at start, every hour, and when finished. I would definitely start by flushing a bit more. If the 1 micron sediment isn’t getting clogged then it’s most likely mineral deposits in the membrane or just a loss of pressure. Does this happen if you take the drinking water portion off line, and vice versa? Do you manually close and open valves to direct where the water goes or does it flow to both brutes at the same time?

I flush mine for a minute until my tds into my resin drops to 5 or 3. Maybe it would help op? I'm not sure if that has to do much with the pressure rather than the membrane life

 

[Spare time]

I'd consider adding a 5 micron sediment filter before the 1 micron. 1 micron will clog faster than 5

 

[a.t.t.r]

Maybe swap the restrictor for a membrane of a larger size. Waste more water yes but get a better constant flush.

 

[A_Blind_Reefer]

Also, with two membranes a booster pump is usually warranted. Did you replace the restrictor when you added the membrane? What gpd are each membrane? Are you certain of pressure? I’ve seen air pockets cause a much higher gauge reading than actually available.

 

[rajdude]

Most suggest flushing for a couple minutes, not seconds. An auto flush flushes for 15-20 seconds at start, every hour, and when finished. I would definitely start by flushing a bit more. If the 1 micron sediment isn’t getting clogged then it’s most likely mineral deposits in the membrane or just a loss of pressure. Does this happen if you take the drinking water portion off line, and vice versa? Do you manually close and open valves to direct where the water goes or does it flow to both brutes at the same time?

Hmmm...I can flush longer.

Mineral deposits? I think I have heard that suggestion in the past. How do get rid or mineral deposits? Or is there a way to only prevent mineral deposits?

Loss of pressure does not seem to be happening....judging from the pressure shown on the gauge right after installing fresh carbon+sediment blocks....and comparing to a few months down the line.

There are 2 solenoid valves right after the T which splits the output of the membrane(s) to the two Brutes. I can independently turn them on/off.

It usually does not flow to both at the same time. I usually fill the fish tank Brute first....but ...depends on if my lovely wife is complaining of no RO water in the kitchen or not ;-)

 

[rajdude]

I flush mine for a minute until my tds into my resin drops to 5 or 3. Maybe it would help op? I'm not sure if that has to do much with the pressure rather than the membrane life

Pressure could be it........but will the membranes get fried due to low pressure?
Isn't 55-60 PSI enough (as measured after the carbon & sediment blocks)

 

[rajdude]

I'd consider adding a 5 micron sediment filter before the 1 micron. 1 micron will clog faster than 5

I could. But does not look like that the sediment filter is getting clogged.......based on non-existent pressure drop.

 

[rajdude]

Maybe swap the restrictor for a membrane of a larger size. Waste more water yes but get a better constant flush.

so yeah, I kinda did that test
I had two membranes, BRS kit: 150 GPD Water Saver Upgrade Kit which has two 75 GPD membranes

I thought the water flow through the restrictor is just too low while using that kit. So, as an experiment, I deleted one membrane, kept the same restrictor: 550 mL Flow Membrane Flush Valve (Recommended for 75 GPD Membranes)
Replaced the membrane to a brand new one.

But after one month, boom! same problem happened.

 

[a.t.t.r]

so yeah, I kinda did that test
I had two membranes, BRS kit: 150 GPD Water Saver Upgrade Kit which has two 75 GPD membranes

I thought the water flow through the restrictor is just too low while using that kit. So, as an experiment, I deleted one membrane, kept the same restrictor: 550 mL Flow Membrane Flush Valve (Recommended for 75 GPD Membranes)
Replaced the membrane to a brand new one.

But after one month, boom! same problem happened.

What is the hardness of the tap water? Temperature? City use any odd chemicals for heavy metal binding or flocculants?

 

[rajdude]

Also, with two membranes a booster pump is usually warranted. Did you replace the restrictor when you added the membrane? What gpd are each membrane? Are you certain of pressure? I’ve seen air pockets cause a much higher gauge reading than actually available.

yes, I changed the restrictor when I added the BRS dual membrane "water saver kit". However, I believe it was the same flow rating.

Both were 75 GPD ..... "were" because now I have only one....as an (unsuccessful) experiment.
The single replacement membrane is the exact same model.

No I am not 100% certain of the pressure. I did not trust the gauge since I have only one. However, I have done extensive testing with Frank. Took the whole kit outside on the deck. I have another gauge which screws straight into the hose bib. It indicated 75 psi. Connected the RO filter straight to that spigot (as a test)...but the RO water production did not increase. That was October last year....so water was not too cold at that time of the year.

The water supply in the basement is from one of the piercing needle type thingy. It has been mentioned as a "suspect" for low water pressure. But that gauge! Maybe I have a bad one?

But if water pressure really is the problem, the RO water production should have increased when I had the system on the deck, right?