[combat1]

Hi all,
Need a bit of advice on my RO set up.
Got sediment, carbon and carbon block filters
2 x 150 gpd membranes, booster pump and a 10’’ di resin vessel.
Made 1000 litres of 18ppm the other day!
Was 34 out of the membranes.
Changed all the filters , flushed them and changed the resin.
Backwashed .
Produced 500 litres at zero but was starting to rise at the end.
Changed the resin and produced another 500 at zero.
Membranes a couple of years old in a high ppm area.
Probably going to have to change the membranes?
Also thinking of changing the resin vessel for an 11 litre one.
Quite high cost on this, so do you think it would be a good move?
Thanks
( I filled the pool with the 1000 of 18ppm!)

[dd]

I don't think those 10 inch resin vessels are good for much. Also sounds like you need new membranes.

[combat1]

Thanks for your help.
Previously filled the 10 inch weekly, now twice or three times a week.
Think I’ll go on the 11 litre vessel.
Cheers

[Don Kee]

Firstly those 10” DI vessels are awful, a larger DI will be loads more practical.

How have you got the membranes set up, in series or parallel?

Personally, I would buy new membranes but also buy another 150gpd and housing to make it a 450gpd RO and then I’d set them up in parallel to make sure that they get even wear.

Cost wise, I’m not sure all of that will cost you much more than £100 (excluding the DI)so it’s not a huge cost to have yourself a more upgraded RO.

[Spruce]

Hi all,
Need a bit of advice on my RO set up.
Got sediment, carbon and carbon block filters
2 x 150 gpd membranes, booster pump and a 10’’ di resin vessel.
Made 1000 litres of 18ppm the other day!
Was 34 out of the membranes.
Changed all the filters , flushed them and changed the resin.
Backwashed .
Produced 500 litres at zero but was starting to rise at the end.
Changed the resin and produced another 500 at zero.
Membranes a couple of years old in a high ppm area.
Probably going to have to change the membranes?
Also thinking of changing the resin vessel for an 11 litre one.
Quite high cost on this, so do you think it would be a good move?
Thanks
( I filled the pool with the 1000 of 18ppm!)

Certainly a bigger DI vessel is important consideration when living in a hard water area - even a must.

It is imperative that you sort your membrane issue out as poorly producing membranes will  deplete your resin quickly having to polish the pure off.

The time to consider replacing membranes is when they are only removing 94% of the dissolved solids in your input water. Ideally a good performing membrane will remove between 97 and 98% of the dissolved solids in the input water. (Example: tap water at 400ppm with 34ppm pure = 91.5% efficient. 400ppm at 94% membrane efficiency = 24ppm pure and at 97% efficiency = 12ppm. You are using 3 times more resin than when having more efficient membranes. With your high tds tap water you must buy the best membranes which I believe are still American made; i.e. Filmtec. etc. IMHO Chinese manufactured membrane aren't the same quality.)

In a hard water area you will probably need a higher waste to pure water ratio when producing pure. My old 450GPD had a fixed inline restrictor at 3 waste to 1 pure although that could be a little less if you are able to manually restrict your waste output.

If you are on a water meter you might have to consider that further restricting the waste output will save water costs at the expense of  membrane 'longevity' and higher resin consumption.

[combat1]

Thanks all, time to upgrade!
Parts ordered, good quality.
Much appreciate your help.