[combat1]

had my ro for about 2years and this time last year added an upgrade to double the production and reduce the waste.
All has been brilliant until now when the resin only lasts about a week before the tds starts to rise.
I change the pre filters often and backflush.
Do you reckon I need new membranes?
I make about 600 - 800 litres a week.
Cheers.

[Steve Sed]

What is the tds before di?

[combat1]

Hi Steve, 43 before going into the di.
I changed to a different supplier of 10'' prefilters and wonder whether that might affect it. I'll give it a go with the originals at the next change.
What should the tds be before the di?
Thanks.

[Steve Sed]

Hi Steve, 43 before going into the di.
I changed to a different supplier of 10'' prefilters and wonder whether that might affect it. I'll give it a go with the originals at the next change.
What should the tds be before the di?
Thanks.

Mine is around 10. I reckon new membranes.

[combat1]

yes looks that way! thanks for your help mate.

[David Lingard]

My tap water is 300tds

I had a 50GPD system to start with and that took it to 39 before the DI

Then i got a 350GPD system and it got to 30 before the DI

Now i put a pump on it and it gets 19 before the DI

I cant imagine your normal tap water is any worse than mine (i think thats why the people around here are like they are) so I would guess on the membranes.

Although it may be worth buying new filters at £20 or so because then if it is the filters you have saved yourself having to buy new membranes, and if it turns out to be the membranes at least you ave spare filters (wich you will proably need eventualy anyway)

David

[Spruce]

had my ro for about 2years and this time last year added an upgrade to double the production and reduce the waste.
All has been brilliant until now when the resin only lasts about a week before the tds starts to rise.
I change the pre filters often and backflush.
Do you reckon I need new membranes?
I make about 600 - 800 litres a week.
Cheers.

Hi Combat

Our water is 90 although a few years ago it was 255. I've had 3 x 150GPD membranes in my r/o for nearly 7 years now. The orginal unit was supplied with a second washer on the top of the chlorine filter. It was as though the original supplier of the r/o (Peter Fogwill) felt that the chlorine removal cartridge was fractionally to small and chlorinated water may have been escaping into the r/o membranes.

I only suggest this as I would have thought that your membranes should last longer than 2 years at your low water tds.

I'm also aware that there are other issues that can also cause premature membrane failure, such as cold, so I keep my unit warm in the winter.

Spruce

[combat1]

Thanks Spruce, you are always good in giving advice to my posts and I appreciate it.
My tap water is around 275.
I'm going to order a new filter set from the old supplier and if that dosent work then i will put in new membranes.
The cost is nothing really when you think what it earns you so not a problem.
Hope you are ok. All the best. Chris.