[sunshine windows]

Changed all the filters and membranes on a 450gpd 10" system and the water is coming out at 100ppm.

I'm almost 100% sure that I've reconnected it the way it came off but I'm baffled as to why the reading is so high.

Does it make a difference if any of the filters are inserted upside down?

All the membranes are the right way in and I'm pretty certain the connections are how they were.

Any help would be appreciated.

Cheers

[Tom White]

How long have you let it run for before measuring the TDS?  It takes a few hundred litres of filtered water to clean out the RO membranes before they settle down to a low TDS.  A couple of hours at least.

Keep it disconnected from your DI chamber while it's initially running off the few first few hundred litres; just to save resin and let all the water down the drain.

[Don Kee]

Double check you've got everything plumbed properly mate
I changed mine last week, Tosh is right you need to let it run for a few hours to let it settle, but mine was initially running at 40 then settled down to 14/15
100 seems high, even without letting it run...

[Smudger]

Last time some one had this they forgot to remove the wrappings off the filters..

Darran

[sunshine windows]

Hi guys,

Thanks for your input.

Smudger,  the wrappers are definitely off 😀

Tosh, I let the system flush for well over half an hour before running it on Saturday (when I changed everything).

It's a good job I checked the reading coming out of the RO this morning as I only checked final reading from di on Saturday.

Purefreedom have sent some new membranes out to me, as this is the only thing I can think it may be (fault membranes).

If it's no good after the new membranes go in, I may have to order a new ro, as I can't understand how this is happening.

Last time I changed everything the reading was 4 from the ro.

[Don Kee]

You need to let it run (producing pure) for an hour or two, not on flush

[Frankybadboy]

You need to let it run (producing pure) for an hour or two, not on flush

only if you got strong hands

private joke

[Spruce]

My suggestion is to strip it all down and then test each membrane individually.

Take the first membrane and connect it up to the line from your prefilters (the carbon block one). The inlet is the one on the screw cap. Then turn your tap on. The water outlet that is flowing the fastest (won't be difficult to identify) is your waste. Connect up that line to your waste that should have a tap or inline restrictor in it. This will 'pressurise' the r/o and you will then be able to check the tds of the pure dribbling out of the other connector after 5 minutes or so (which is your pure).

As you test each one you will get an idea of which membrane is at fault which could be a non seating seal on the membrane. The main seal around the membrane it the most important, but check the 2 o rings on the other end. Have they got damaged? We used to wipe a minute amount of vaseline around those o rings to help them slide into the housing tube. Silicone grease is best though.

I don't know how Purefreedom connect their r/o's up but it appears that there are 2 common ways.

The first is to connect all the membranes up in parallel. This simply means that the inlet from the prefilters is split into 3 (or the number of membranes you have). Each then goes to the inlet of each membrane housing.
On the other side each pure outlet is connected together to form one tube to the DI vessel and the wastes are connected together before they go the the inline restrictor/tap/flush valve.

The second is that the first two membranes are connected in parallel (as above) but the third is different. The wastes from the first two membranes are feed into the inlet of the third membrane. The pure outlets are all connected together and the waste from the third membrane goes to the restrictor/tap/flush valve.

Then there is a third way of connecting the membranes up - in series. This is when the outlet from the prefilters is connected to the inlet of the first membrane. The waste from the first membrane is connected to the inlet of the second membrane. The waste from the second membrane is connected to the inlet of the third membrane. All pure outlets are connected together and the waste from the third membrane goes to the restrictor/tap/valve.

Most suppliers use colour coded tube to connect the membranes which does make it slightly less difficult to suss out.  

[Tom White]

And maybe stick a pic up of how your RO is connected.  I'm pretty dudish with regards ROs now, after I had problems with my own.

They're not complicated.

Good advice from Spruce about testing each membrane individually and to actually run the RO in filter mode and not flush from Don Kee.

[George Gardner]

Sunshine - having very similar problem, did you get to the bottom of it??

[EandM]

In the old days of the Merlin the membranes sometimes wouldn't seal properly - they looked like they had but some water was leaking past them. It happened to me twice. Appreciate you're not using the same but try dismantling and reassembly.

[Dannymackreturn]

I've got a 450gpd I changed resin and filters last month didn't wait long came out to 000 pretty soon

[sunshine windows]

Just received delivery of the new membranes. I'll let you know how things are once I've change them again.

Cheers everyone

[Don Kee]

You need to let it run (producing pure) for an hour or two, not on flush

only if you got strong hands

private joke

You've had more practice building those forearms up, although the right one is bigger than the left

 

[sunshine windows]

Well, I've just changed the membranes over, swapping exactly how they were before.

It was definitely a membrane problem, or they were somehow not seated properly.

The water from RO has now reduced to 16, still not great though considering the last time I changed everything it was down to 4.

At least it's not pumping out the RO at nearly 100 anymore 

[sunshine windows]

Had the system flushing for ages today and just started producing pure, finally it's brought the reading down to 6.

Happy days again 

[sunshine windows]

The RO that is!