Eating Up RO Membranes

[rajdude]

Yeah, I rewired the RO-DI stuff yesterday.......got it working again. Waiting for the drum to fill up so I can do a large water change today.

 

[flyfisher2]

Sounds good. Have you checked your post membrane pre DI TDS?

 

[rajdude]

I have a comment about these water pressure gauges..... I have one too and I have found out that this is not a reliable way of checking what is going on in our RO-DI filter system.

Like most, my gauge is installed in an QC Tee fitting which is installed in the tubing going straight to the membrane's input. All good there...it reads around 80 psi.

Here is what I found out while troubleshooting:
That gauge gives a misleading description of "pressure". I put that in quotes because although it does read the "pressure" correctly, the "flow" of water is a different story.... I may be getting 80 psi, but I still have low water flow! < that is the problem.

How I found out?
Well, while troubleshooting, the vendor wanted me to measure my house's water pressure. So I disconnected that gauge and put it straight into the water inlet of the ro-di filter. of course it was reading the same - 80 psi. But we noticed that if I let that inlet tubing run into a bucket, the flow of water coming out of that tubing was not very strong. It is not a trickle, but sure not what whoooshing water flow, which we should see instead.

So there you have it. These gauges are surely measuring the pressure...which builds up in a couple of seconds... visible by how the needle "ramps up" when first connected to the water lines....but your ro-di filter may not get enough water flow through those lines!

BTW, The problem has been identified. I have the peircing needle type tap (which is commonly found in most plumbing)....and that is probably corroded or blocked enough to not let a large flow of water through. Plumbers don't like that part. They rather have a proper Tee fitting soldered into the pipe and a under sink faucet or a spigot soldered there, feeding the RO-DI filter.

YMMV :)

 

[rajdude]

Sounds good. Have you checked your post membrane pre DI TDS?

Yes. I have one of those HM triple probe electronic meter plumbed into the system (in addition to a handleld meter):

TDS readings:
Inlet water: 190
Output of membrane (pre-DI): 8
Output of DI stage: 0

I really need to buy a good chlorine test kit.

 

[Snoopy 67]

https://www.bulkreefsupply.com/john-guest-angle-stop-valve.htmlThis is the proper way to plumb water to your RO unit.

 

[flyfisher2]

I have a comment about these water pressure gauges..... I have one too and I have found out that this is not a reliable way of checking what is going on in our RO-DI filter system.

Like most, my gauge is installed in an QC Tee fitting which is installed in the tubing going straight to the membrane's input. All good there...it reads around 80 psi.

Here is what I found out while troubleshooting:
That gauge gives a misleading description of "pressure". I put that in quotes because although it does read the "pressure" correctly, the "flow" of water is a different story.... I may be getting 80 psi, but I still have low water flow! < that is the problem.

How I found out?
Well, while troubleshooting, the vendor wanted me to measure my house's water pressure. So I disconnected that gauge and put it straight into the water inlet of the ro-di filter. of course it was reading the same - 80 psi. But we noticed that if I let that inlet tubing run into a bucket, the flow of water coming out of that tubing was not very strong. It is not a trickle, but sure not what whoooshing water flow, which we should see instead.

So there you have it. These gauges are surely measuring the pressure...which builds up in a couple of seconds... visible by how the needle "ramps up" when first connected to the water lines....but your ro-di filter may not get enough water flow through those lines!

BTW, The problem has been identified. I have the peircing needle type tap (which is commonly found in most plumbing)....and that is probably corroded or blocked enough to not let a large flow of water through. Plumbers don't like that part. They rather have a proper Tee fitting soldered into the pipe and a under sink faucet or a spigot soldered there, feeding the RO-DI filter.

YMMV :)

I know I'm not the most qualified to answer this and I'm hoping that the others are reading and will chime in. The way I understand it, pressure is pressure. Your kitchen faucet will release it differently to your garden hose or your bathtub faucet. The tiny 1/4" tubing on the RO will hold it back more as well. Even if your pipe were totally blocked the pressure will build to a maximum and that determines your homes pressure? As I recall when my home was built the inspectors connected a pressure gauge and left for a couple days to verify the pressure and I guess make sure the plumbing could withstand it.

 

[rajdude]

..........and ......I still do not get any notifications for this thread! :-(
Funny, I got a notification for another thread I posted in....."

Dumb things the LFS has told you​

 

[KStatefan]

Pressure gauges can tell you a lot about your system. I use two gauges one prior to my filters and one at my membrane. If the differential between those two get to high i know I have a filter restricting flow. If you only have one pressure gauge you can compare static and dynamic pressure.

I "fixxed" a lot of ice makers back in the 80s due to plugged saddle valves when I worked at an appliance store part time after school.

 

[flyfisher2]

UPDATE: it's been a month and my post membrane is reading at 5PPM. I've produced 14 Brutes at about 25 gallons each. Went through one canister of DI and just put in a fresh one. Not bad in my book?

 

[Woodyman]

UPDATE: it's been a month and my post membrane is reading at 5PPM. I've produced 14 Brutes at about 25 gallons each. Went through one canister of DI and just put in a fresh one. Not bad in my book?

That's great to hear! What's your chlorine reading after a month?

 

[flyfisher2]

That's great to hear! What's your chloride l chlorine reading after a month?

I'll check.... whoops! totally forgot to do that. Haven't changed anything other than DI so this should be interesting.

 

[flyfisher2]

I'll check.... whoops! totally forgot to do that. Haven't changed anything other than DI so this should be interesting.

Okay here we go…

 

[Woodyman]

Okay here we go…

Looks good, check again next month!

 

[rajdude]

@flyfisher2
Any update on the system?

Mine..I got bad news. I have managed to fry my THIRD membrane. I am not sure what is happening.
I added another stage of carbon block
Replaced all pre-filters, sediment, carbon blocks with new ones...new membrane.
Still, after about a month, same thing happened.....membrane is not producing anymore.
TDS before 180
TDS after 7
TDS after DI 0

I am producing maybe less than 30 gallons a day.

I am at the end of this rope....not sure what else I can do. Talked to the original vendor multiple times (PureWaterProducts) also talked to BRS, trying to talk to SpectraPure also (waiting for a response)...........so far no one knows what is going on!

 

[Woodyman]

@flyfisher2
Any update on the system?

Mine..I got bad news. I have managed to fry my THIRD membrane. I am not sure what is happening.
I added another stage of carbon block
Replaced all pre-filters, sediment, carbon blocks with new ones...new membrane.
Still, after about a month, same thing happened.....membrane is not producing anymore.
TDS before 180
TDS after 7
TDS after DI 0

I am producing maybe less than 30 gallons a day.

I am at the end of this rope....not sure what else I can do. Talked to the original vendor multiple times (PureWaterProducts) also talked to BRS, trying to talk to SpectraPure also (waiting for a response)...........so far no one knows what is going on!

I'd be happy to help you troubleshoot like we did with @flyfisher2

How old is the unit itself meaning all the hoses/connectors/housings etc.

Do you have any pictures of your setup and/or a diagram of flow through your system?

You said you put in all new filters, what do you currently use to monitor your stages and do you know what your incoming water parameters are?

The numbers you posted aren't bad, but you mention the membrane stopped producing. If you are getting no flow from the RO side how much is flowing down the reject line? This could be that your membrane is clogging with debris or isn't seated properly.

Anyways will be happy to help you troubleshoot.

 

[flyfisher2]

I checked mine yesterday and 6 was my TDS POST membrane as of yesterday.
So far so good
I’ll be checking my chlorine post carbon blocks soon and posting my results.
WOODYMAN work your magic and pull him through!

 

[Woodyman]

I checked mine yesterday and 6 was my TDS POST membrane as of yesterday.
So far so good
I’ll be checking my chlorine post carbon blocks soon and posting my results.
WOODYMAN work your magic and pull him through!

It was not just me that helped. But happy to lend a hand where I can.

 

[DrZoidburg]

@rajdude What is the membrane gpd rating? 7/180 is pretty good rejection rating.

 

[flyfisher2]

Two months in. No changes and TDS holding between 5-6 post membrane.
Zero on chlorine.

 

[Woodyman]

Good news!