Do RO/DI units need to be flushed out ?

[Malibu361]

Thanks ,I will give that a try but as I said b4 it is not flowing out of the RO membrane...Could the Carbon filter still be suspect..?

 

[Josh]

I've had 1st and 2nd stages clog in a day, it usually happens when they are doing work on the pipes in my building. I clear the water line by running the sink for up to an hour and it still clogs. The PPM can stay at 80-160 for an entire week!

Also, contrary to what everyone else says, I run my water freezing cold and only at 30 PSI and it seems to work fine.

Finally, do not run water through just the RO final stage while testing for very long as chlorine damages it extremely quickly.

 

[Solace Aquatics LLC]

Thanks ,I will give that a try but as I said b4 it is not flowing out of the RO membrane...Could the Carbon filter still be suspect..?

It sure can, because the RO membrane is typically the 3rd stage in the filtration process putting it after the carbon, therefore it may be blocking the pressure needed to run the RO properly. If there is NO or very LITTLE waste water than it is most likely one of the cartridges before the RO Membrane.

You can tell if it is the carbon or any cartridge before the RO membrane by simply checking your waste water output. It should be relatively fast if you are running your RO at a good PSI.

I run my RO/DI unit at 60 PSI with a Booster Pump, but that is what the manufacturer recommends. If possible, I would get a hold of the seller and see what they recommend for operating specs. If you need a gauge to test your water pressure, I have one you are more than welcome to borrow.

Also ask the seller for a plumbing diagram and double check it against your current plumbing, just to ensure the water is flowing the right direction.

A Automatic cut off valve will reduce the units operating pressure, if you have some extra 1/4" RO tubing, I would suggest replumbing the unit without the auto cut off valve to see if the problem persists. If it does, you kow it is NOT the valve and you can move on to trouble shooting another component.

 

[Buckeye Field Supply]

I've had 1st and 2nd stages clog in a day, it usually happens when they are doing work on the pipes in my building. I clear the water line by running the sink for up to an hour and it still clogs. The PPM can stay at 80-160 for an entire week!

Also, contrary to what everyone else says, I run my water freezing cold and only at 30 PSI and it seems to work fine.

Finally, do not run water through just the RO final stage while testing for very long as chlorine damages it extremely quickly.

Yikes! That pressure and temperature does affect the way your system performs.

We have a caluclator on our website where you can plug in your temperature and your pressure and see how much your membrane should produce under those conditions.

A 75 gpd Filmtec membrane, as an example, given feedwater at 30 psi and 55 degrees F, will only produce 26 gallons a day. The rejection rate of the membrane will be adversely affected as well, and you'll go through DI resin faster than would otherwise be the case.

If you don't have a Filmtec membrane, the effects of low pressure will be worse.

Russ

 

[Buckeye Field Supply]

NaCl - are you using a Aquatec booster pump? If so, that pressure is adjustable, and you could take better advantage of the pump by cranking it up higher (no higher than 90 psi).

 

[Buckeye Field Supply]

My unit is fairly new about 2 months, I use it to make between 20-50 gallons a week since I have had it and yesterday I started makin water and it is taking SUPER long .Then I noticed my DI chambers are not full with water like usual and I took it apart and bypassed everything just to see if there was outflow and there is now non at all just from the waste line .What can this be from ?Could I need a new RO filter already,could it be clogged I have no idea what to do and the manufacturer has not asnswered my emails....! Any help would be greatly appreciated..Thanks Sal

Sal - I scanned the whole thread and I don't think I saw you report what your water pressure is. If may be low to start out with, and then if you reduce it further by having some at least partially clogged prefilters, and you throw on top of that cold winter tap water ---Yes - your system could grind to a halt.

If you don't have a pressure gauge on your system - now you know why you should! You can add one very easily and they are inexpensive.

Russ

 

[Buckeye Field Supply]

A Automatic cut off valve will reduce the units operating pressure...

Pressure gauges are typically installed after the prefilters and before the membrane - so an automatic shut off valve would not affect the pressure on the gauge.

 

[Malibu361]

How much do you sell the pressure gauge for?I run cold tap water through my Ro and have done the same since I purchased it there have been no change at all except for the performance...As I said earlier when I do a reverse flush for a few minutes then switch everything back it will work for a limited time .....I have ran through every piece basically and it seems as if no water will flow from the Membrane except waste ..could it be bad filters after 2 months..??

 

[Buckeye Field Supply]

I suspect all or one of the following: cold water, low line pressure, and/or clogged prefilters. Our pressure gauge kits are $11 or $18.

 

[Malibu361]

So ,If cold water was the culpret why do they say to hook up an RO system to the cold water feed on a pipe? and how could pre filters be suspect if it flows through the first 3 with no problems but jams up at the membrane?Could the membrane be bad as well this early on? Please send me a link in a pm to your gauge kit ....Thanks ,Sal

 

[Buckeye Field Supply]

Temperatures over 113 F void the Filmtec warranty - the TFC elements are damaged by hot water.

W/O a pressure gauge you have no way of telling if it is flowing through the prefilters "no problem." It may be flowing through them, but at a reduced flow and pressure compared to when they were new. That, teamed up with the fact that you might have low pressure to begin with, may be enough that you don't have the pressure necessary to push the water through the membrane.

Filmtec membranes are very good - we just don't run into problems with them. Unless you have something that would affect your membrane (I ran down a bunch of potential culprets in my post above), I would not suspect the membrane is clogged. Could be biofouled - that is something you can check (see above).

I'll send a PM now.