[nathankaye]

Ive seen no end of threads on here about problems after doing a membrane change on RO's. Ive even added some advice myself (perhaps wrong of me now  ).

I have a 450gpd Purefreedom RO. When i first set it up, i was imformed to run it for a couple of hrs before using pure, inorder for it to wash of whatevers.....
My tap is close to 300 (long time since ive taken a reading), when it was new and without booster pump it was reading 009 before di. Im now replacing membranes as its hitting 015 with booster pump.
 But since changing them, im using a booster and still getting a reading of 016.
Ive;     backflushed, bled piped to get any air out (think ive done it right), double checked all in n out connections and still nothing. I had to crank open the housing but ive only hand tightened them back up. Could this be the problem?? Do i need to run it for a couple of hrs to make sure new membranes are rinsed?? Also theres a drop in psi, used to be 70 after pump but now only 50.

Did all the ones who had similar problems eventually solved their issues with this?? Any helpful advice appreciated.
Cheers

[Don Kee]

Assumimg you have plumbed it all in correct, restrictor is working, and you've flushed the membranes for a while before you've set it to produce; the only thing that you can see that is different (according to your post) is your water pressure is lower than before?

I think you're asking the wrong question, as you've already found the reason for your higher pure TDS...


What you should be looking into is why you have a lower input pressure...
Have you changed your pre-filters, any leaks, have you turned your fully closed your waste valve/tap & have you tried increasing your pumps pressure..?

[Og]

Changed hose between tap and ro?

[dazmond]

cant you just use DI only?

[Mick Kent]

cant you just use DI only?

He cant at 300ppm st tap Daz

[nathankaye]

Its just so frustrating.  I turned it off last night and will try again this evening.

Everything is reconnected as it was prior and so i will try and tighten some more, though i have no leaks. Im wonderi g if i still have some air left in somewhere which is accounting for low psi as nothing else has changed.

[chris turner]

Don't you have the 300 or 450gpd system?
I use to always get the same problem with these systems, it was always down to not tightening enough. It may not be leaking on the outside, but on the inside water would be leaking through the rubber seals between the housings, causing contamination and lack of pressure.
Also make sure the rubber seals have not deteriorated and always clean them on every occasion you open up the housing as they build up with gunk.

[slap bash]

Is your tap to RO hose not a little frozen and remember colder water is dense so will make it more difficult for your pump to cope than is hotter months.. I find my RO slower in the winter. I fitted the 150 gal membranes to my 450 and my water production is much better. I guess you also have these fitted.

[p1w1]

My old 450gpd system used to  slow down in the very cold by quite a bit, doesn't help with all the connections needed for all the membranes either in regarding little leaks, think about investing in a 40/40 a much better system .

[combat1]

I have this problem every time I change the filters.
Really frustrating!
I'm pretty sure its air somewhere in the system.
Bled it several times, changed all the filter rubber seals and used silicone grease on them.
Booster currently runs at 40 psi with the drain tap fully open.
I have partially closed it now and the pump runs at 80 psi.
Not ideal but producing at the same rate as before the filter change.
Real pain this problem - had to leave it for a couple of days and calm down.
Hope we get the answer.

[nathankaye]

Cheers for all the advice.

I have 3 x 150gpd membranes. I found i had a little trapped air still left in and then i retightened all housings of membranes and that seems to have done the trick 

I would love to upgrade my RO, but at the moment this for the money is doing a grand job for my liking. Now that i have it how it should be.  Especially when funds are needed elsewhere. But when my van dies, im thinking of upgrading to a van fitted supply system. Quicker n less storage for me to sort out. But thats a bit far off at the moment.

[Dave Willis]

Maybe you have one duff membrane in there, I would check the tds out of each one.