Testing RO

[Bricklayer]

I just finished putting together my single membrane 4x40 RO. I would like to do a test run before I put it in the RO closet in the shack. Just want to make sure all connections are water tight and pressure switches work as they are supposed to. I really don't want to be running all over the place for parts during the season. What is the best water to use to test. I would like to test it under pressure. I've read distilled water works but with that there will be no permeate. I have well water with no chlorine. But am not sure of the mineral content and tds of it. It's not softened. My neighbour has softened water but is there a certain level of softness I need to check before I use it.
Thanks

[wiam]

Why would there be no permeate with distilled water?

[Bricklayer]

Sorry. Explained that wrong. It would all be permeate would it not? Distilled water is basically permeate anyways? Could I actually operate the RO at pressure running basically permeate through it? I'm not looking to rinse the RO but basically test it under pressure so I would like it to have some concentrate flow. I just thought it was bad for the Membrane to run permeate at high pressure.

[Urban Sugarmaker]

You should see some portion of the water coming out of the permeate port, and the other portion out of the concentrate port. The membrane won't change anything here because there are no solutes in distilled water (ie the permeate and concentrate are the same). At least you can test for leaks, calibrate pressure switches, and make sure your plumbing is working as planned.

I never heard it was bad to run distilled water under pressure, but I don't know. But if you are testing now, just remember you have to keep the membrane wet for the rest of its life. Even with distilled water, you may want to use the preservative solution since the season is months away. Search threads on here for guidance on storage vessels you can make yourself and preservative solution.

[Bricklayer]

I plan on keeping the membrane in the pressure vessel wet. I have two extra pressure vessels I could use as storage vessels if need be but I think leaving it in is the best route. Keeps all the seals on the unit wet. I plan on storing the RO in my basement so I can swap the solution out halfway through the offseason to freshen it up.

[maple flats]

Use the preservative and you will have no need to switch or change the fluid. While the distilled water is pure, you likely touched the pre filter, the membrane and other components which could have contaminated the system, the preservative (it is fairly cheap) will prevent issues.

[PerryFamily]

I have "concentrated" my well water several times without issue. There really isn't much pressure as there is no sugar , it's basically just to make permeate for the final soap wash and rinse of the membranes and to mix the preservative for storage.

[wiam]

I concentrate permeate after every rinse. That is how I tell if it needs a wash. Use the same pressure and permeate flow and see what the concentrate flow is. Lapierre has a temp correction chart for this on their site somewhere.

[Sugarbush Ridge]

When I picked up my RO from Ray Gingerich he demonstrated to me how it worked. He had some water,, 5 gallons???,, in the wash tank. He has both concentrate and permeate lines going back into wash tank reusing water over and over. Showed how turning pressure up too high shut off or if intake was shut off how pump also shut off. That would not require a lot of water but you could look for leaks and check cutout switches and just play with adjustments. True you have no real concentrate to affect pressure. But then you would need to put in some preservative.

[Bricklayer]

I assume the process for filling unit with preservative is just like giving unit a soap wash? Mix solution, circulate solution for 5-10 minutes then shut system down and close intake valve, permeate valve and concentrate valve. mine has valves on permeate and concentrate and intake so I can easily move RO without getting water everywhere.

[wiam]

I assume the process for filling unit with preservative is just like giving unit a soap wash? Mix solution, circulate solution for 5-10 minutes then shut system down and close intake valve, permeate valve and concentrate valve. mine has valves on permeate and concentrate and intake so I can easily move RO without getting water everywhere.

That is pretty much what I do when I shut mine down.

[PerryFamily]

Although my RO room is heated I pull out the membranes and store them in PVC vessels I made.

I don't see why you couldn't do it the way you described
Not sure how the preservative effects pressure switches or pumps though

[Bricklayer]

What is in the preservative solution? Glycol? I would assume it would have a pretty neutral PH level.