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Ro membrane

Hi guys

My tds going to my membrane is 350tds

What should it be after membrane think they are shot?@spruce

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With the right water pressure and enough volume then a good membrane should remove 97 to 98% of the TDS of the input water.

So your pure would be around 7 to 11ppm with 350ppm input tds..

As the efficiency of the membrane drops with age your rejection rate will increase. It was once said by an experience wfp supplier some 15 years ago that he felt the cutoff point was around 94% or 20ppm in your case. By that time the resin you use polishing those 20ppm off will negate any savings of buying new membranes.

But it might be 90% if you aren't processing much water.

In days gone by a new Merlin r/o out of the box only delivered an efficiency of 90% and dropped lower with age.

 
How old is the membrane, what did it used to produce as your water pressure dropped? Your membrane defo sounds goosed TBH.

for example my tds is between 290 and 330 it fluctuates 

Tap pressure is 69 psi 

2 years ago I was producing approx 007 at 60% waste to 40% pure.

2 years later I’m producing 009 at approx 3l waste to 1l pure.

 
Depends which size and brand you are using Halton. Wherever you buy it from will give the the exact answer but you need to monitor how much water passes through it - I use the fibredyne 20” carbon filter which has a life of approx 75000 litres of water (waste and pure combined) I’ve used ones in the past that only last 3000ltrs


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Depends which size and brand you are using Halton. Wherever you buy it from will give the the exact answer but you need to monitor how much water passes through it - I use the fibredyne 20” carbon filter which has a life of approx 75000 litres of water (waste and pure combined) I’ve used ones in the past that only last 3000ltrs


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Never thought of that good thinking
Well pre filters changed awaiting membranes see what happens.
Cheers chaps

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