Flushing RO membrane

[WhiskeyCoffee]

Hey everyone, I just ordered the AquaFX Barracuda system and I'm pretty excited to soon have 0 TDS DI water for my reef. I've been reading about flushing the RO membrane every so often to get more life out of it. Is this absolutely necessary right away if my tap TDS is only ~80 ppm?

Also I find the installation process extremely confusing and was wondering if someone can explain it to me like I'm a idiot...

 

[Reeferdood]

Not necessary but here is a video I found on youtube that might explain it a little better...

 

[Bbaz123456]

I don't think it's necessary bit supposedly will extend the life. I may be completely wrong but what I do is pull the flow restrictor off and let it run for a minute. Somebody please correct me if that not the same thing as what all the extra valves do.

 

[Maximizer]

Flushing is necessary. Everything that the RO is removing, has a chance to stick to the membrane/feed spacer. By flushing it you get higher cross flow across the membrane and will help pull anything that stuck to the membrane, off and flush it out. Pulling off the flow restrictor does exactly that, its just a little easier to add a valve and some tubing then have to pull that apart all the time. If you don't flush the RO, you can really shorten the life of the membrane.

 

[WhiskeyCoffee]

Flushing is necessary. Everything that the RO is removing, has a chance to stick to the membrane/feed spacer. By flushing it you get higher cross flow across the membrane and will help pull anything that stuck to the membrane, off and flush it out. Pulling off the flow restrictor does exactly that, its just a little easier to add a valve and some tubing then have to pull that apart all the time. If you don't flush the RO, you can really shorten the life of the membrane.

I'm going to quote @AZDesertRat on another forum:

Flush kits are a waste of your hard earned money. In theory they sould like they would work but in reality bypassing the flow restrictor does not provide the pressure, volume or velocity needed to scour the membrane. They also do absolutely nothing at the beginning as all they do is flush the waste side of the membrane, TDS creep resides on the treated side of the membrane so it does not help save your DI resin.

If you want something that really does something get a DI bypass valve which installs between the RO membrane and DI filter so you can flush the TDS creep out before it hits your resin and wears it out prematurely.

Most long time knowledgeable vendors don't waste your money with so called flush kits since all it does is give you a warm fuzzy feeling. There is no documented proof they do anything other than lighten your wallet.

 

[Maximizer]

I'm going to quote @AZDesertRat on another forum:

Flush kits are a waste of your hard earned money. In theory they sould like they would work but in reality bypassing the flow restrictor does not provide the pressure, volume or velocity needed to scour the membrane. They also do absolutely nothing at the beginning as all they do is flush the waste side of the membrane, TDS creep resides on the treated side of the membrane so it does not help save your DI resin.

If you want something that really does something get a DI bypass valve which installs between the RO membrane and DI filter so you can flush the TDS creep out before it hits your resin and wears it out prematurely.

Most long time knowledgeable vendors don't waste your money with so called flush kits since all it does is give you a warm fuzzy feeling. There is no documented proof they do anything other than lighten your wallet.

With the 20% recovery rate most of us are running on our ROs, you have great cross flow across your membrane that will more than likely keep everything from attaching. A flush kit shouldn't be more than $10( a valve, small section of tubing, and 2 tees.) With a flush kit, your going to allow more water to pass through the element(compared to normal operation) which will create more velocity and "hopefully" pull some more things up. I can only speak from experience and knowledge. I would have to run an antiscalant balance to tell you for sure if a flush kit is worth it for you. The only time you will have TDS creep is when first starting up the RO after it has sat, so a DI bypass valve would work fine and recommended. I have a drinking water tap before my DI that i flush with before pushing it through my DI resin. So yeah you are paying for a fuzzy feeling, but from my experience, it was money well spent for me and only cost a few bucks. Up to you, but i would make my final decision on, what kind of tap water you have and make sure your pre-treatment is up to spec and in good working order.

 

[cromag27]

I would have purchased the $25 spectrapure over the aquafx.

 

[Salty1962]

I flush mine to 20-30 secs. before each use. My DI is still going after a year of use.

 

[WhiskeyCoffee]

I would have purchased the $25 spectrapure over the aquafx.

A $25 RODI system?

 

[Reeferdood]

I think he was talking about the membrane

 

[Buckeye Hydro]

Looks like there are people confusing a few different issues: 1) rinsing a membrane when first installed, 2) flushing a membrane by temporarily bypassing the flow restrictor on the waste water line, and 3) addressing TTDS creep with a DI bypass. Three very different issues...

Russ

 

[Maximizer]

Looks like there are people confusing a few different issues: 1) rinsing a membrane when first installed, 2) flushing a membrane by temporarily bypassing the flow restrictor on the waste water line, and 3) addressing TTDS creep with a DI bypass. Three very different issues...

Russ

I don't see the confusion. We're you referring to me? Three different issues but can be resolved fairly easily.

 

[Buckeye Hydro]

No - just reading through the entirety of the thread...

Agreed - all three easy to address.

 

[Maximizer]

No - just reading through the entirety of the thread...

Agreed - all three easy to address.

Okay. Just wanted to make sure lol

 

[WhiskeyCoffee]

Looks like there are people confusing a few different issues: 1) rinsing a membrane when first installed, 2) flushing a membrane by temporarily bypassing the flow restrictor on the waste water line, and 3) addressing TTDS creep with a DI bypass. Three very different issues...

Russ

What's the difference between the second two and how are they achieved?

 

[Buckeye Hydro]

A flush valve is on the concentrate ("waste water") line. By opening a flush valve you allow the concentrate to bypass the flow restrictor and full pressure feedwater to rush through the RO element and housing.

A DI bypass is a valve on tube carrying RO water. When opened, it re-routes RO water away from the DI and to a drain.

Russ