RO Help - Membrane not lasting

[ShropsWindowCleaner]

Ok great, thanks. If my water pressure is low and I don't use a booster and so have a relatively high output tds, does that inversely affect the membrane or just mean I'll be using more resin? Thanks 

Hmmm, i’m not sure mate. @spruce would know. I’ve only dealt with my Merlin membranes. And with those, the higher the pressure the better they perform. Your question is will low pressure over a long period of time affect the membrane? I would say no, but they won’t perform as well as they should. As i say, i’m sure Spruce can provide more insight, he is far more experienced at producing water than I am!

 

[spruce]

Hmmm, i’m not sure mate. @spruce would know. I’ve only dealt with my Merlin membranes. And with those, the higher the pressure the better they perform. Your question is will low pressure over a long period of time affect the membrane? I would say no, but they won’t perform as well as they should. As i say, i’m sure Spruce can provide more insight, he is far more experienced at producing water than I am!

Ok great, thanks. If my water pressure is low and I don't use a booster and so have a relatively high output tds, does that inversely affect the membrane or just mean I'll be using more resin? Thanks 

If your membrane isn't working within the pressure window then it could well mean your membrane's longevity will suffer. By how much? The answer is how long is a piece of string? How long would it have lasted at the correct pressure? Nobody can answer that as we don't have a sliding doors situation where we can compare 2 different scenarios at the same time under identical conditions. The mineral content of your water could be a lot different to the mineral content of another window cleaner in a different area.

It could well be that @doug atkinson may have a gut feeling on this with his vastly more experience with membrane sales and manufacturers product info that we wouldn't have access to.

All I know is that mine is working at the bottom end of the working pressure window (50psi) and mine is 8 years old and still producing water at a rejection rate of 97% (it was 98% to begin with). If my water pressure was 60psi, would my membrane last longer? I don't know.

You will definitely use more resin to polish those higher tds results off.

The most important part of membrane care is replacing the sediment and carbon filter before their service life expires.

 

[doug atkinson]

Ok great, thanks. If my water pressure is low and I don't use a booster and so have a relatively high output tds, does that inversely affect the membrane or just mean I'll be using more resin? Thanks 

If you have low pressure then it does effect the rejection rate. How longs does it take to do a litre of pure and waste

 

[spruce]

Ok great, thanks. If my water pressure is low and I don't use a booster and so have a relatively high output tds, does that inversely affect the membrane or just mean I'll be using more resin? Thanks 

At 50psi my r/o was producing 2lpm of pure and slightly more of waste.

 

[Paul Symonds]

If you have low pressure then it does effect the rejection rate. How longs does it take to do a litre of pure and waste

It takes about 1 minute to do a litre of pure, need to check next time I fill up for the waste. 

I've also just measured the tap pressure and it's at 40 psi. That's low isn't it? 

 

[Algie]

looking to replace my 20 inch pre filters for the first time.

Can anyone recommend some please .

 

[doug atkinson]

It takes about 1 minute to do a litre of pure, need to check next time I fill up for the waste. 

I've also just measured the tap pressure and it's at 40 psi. That's low isn't it? 

If it is 40 PSI then you should be getting around 2 litres a minute. Measure your waste as may be too high

 

[Iron Giant]

looking to replace my 20 inch pre filters for the first time.

Can anyone recommend some please .

Read this topic 

 

[spruce]

Read this topic 

Exactly!

 

[Paul Symonds]

If it is 40 PSI then you should be getting around 2 litres a minute. Measure your waste as may be too high

Hi doug, just measured again. 

I'm actually getting 1 litre of pure at about 44 secs and 1 litre of waste at around 32 secs. 

Is there a problem there? 

Thanks. 

 

[Part Timer]

Hi doug, just measured again. 

I'm actually getting 1 litre of pure at about 44 secs and 1 litre of waste at around 32 secs. 

Is there a problem there? 

Thanks. 

That's virtually 60-40 waste to pure, which is the recommended levels