[pure-water]

Hi guys

A friend who first got me interested in WFP cleaning has still got most of the equipment he had 4 or 5 years ago. Matts DIY site inspired him as he was and is still on a tight budget.
He fills the tank in his van each night ready for next day.

Not getting quite enough water, he’s been thinking   Shall I, shan’t I.  Shall I, shan’t I.   Can I, should I.   A lot of money to waste if it doesn’t work

Here is the problem you might be able to help with.

He’s got 200 GPD RO system
Having just bought a 100 GPD up grade Kit (100 gpd Membrane & a 100 gpd Membrane Housing) plus 2 new membranes to replace his old ones.

Water comes out of his old membranes before the resin at 12TDS.

Problem is, that whatever configuration he has the membranes (all 3, just 2 or even only 1) he can’t get the water to come out less than 44TDS.

If we swap the new membrane for the old one, the water comes out at 12.

Why wont his NEW membranes be at least as efficient as his old ones. I’m sure all 3 can’t be defective.

Just in case anyone is thinking, it was connected up perfectly

So why 44 out of new ones and 12 from the old?
What should he do?

Thanks, Martin

[mark dew]

They need flushing through 1st.
Check the tds after using them for 10 mins or so.

[pure-water]

Thanks for replying.

That’s the First thing we did.

Since then with all we did they have been flushed for a minimum of about 10 hours with all the trouble we had?

[Pj]

Well, I know it sounds long winded, but I would take it all apart and assemble it again, checking every connection as I go.  I would make sure the pre-filters are new too.  You just have to rule out all possibilities even though they are improbabilities.  making sure that the RO isn't getting a backwash of waste somehow.
If poss..try taking a reading from water gone through just the membrane on its own.  First the old one, then the new one.  If after trying everything else you get a different reading then your new membrane is damaged/faulty.

[matt]

i have the same issue

old RO output was 007

new RO output is sometimes 015

ive tried everything, i came to the conclussion that the new RO isnt as effective as the old

[Alex Gardiner]

What make were the new membranes?  Some types are set up to provide fast production, lower quality than others.

[pure-water]

The make is Filmtec, same as before.

So it could be a flow related problem if as you say it might be designed to work for faster production.

Thanks