RO Membranes life expectancy and cleaning

[PhilC]

In the process of evaluating refurbishing or replacing my watermaker. Existing unit is 14years old. I think original membranes. 3 x 2.5" x 21". Produces 100l/hr (26.5gal/hr) at 900PSi (60ish bar) in water at 25deg C (77F)

What's the life expectancy of membranes?
This production appears low, thoughts on treating old membranes. If treating, what would you use?
Recommendation for a source for membranes that is either in NZ or would ship internationally.
Thoughts on membranes not made by duPont?

[Jimbo2010]

You CAN NOT clean them.

the only way to check it properly is with a TDS meter, reading should be taken with new membrane that reading is your base.

see where goes from there, change when reading is 7-10 points higher

[GreenWave]

Yes use a TDS meter. Best to get a calibration solution. Anything under 250 ppm is certainly drinkable. There are cleaning solutions and pickling solutions widelay available. Google is your friend for local sources.

[pbiJim]

They can be cleaned with acid & caustic.



14 years is much longer than membranes normally last, even when they are cared for perfectly & pickled properly for longer term storage.

[Jimbo2010]

I use a NovaFilters.com RO, I get less than 20 on TDS

[nuku34]

for NZ available parts:
https://www.openoceanwatermakers.co.nz/
My guess it the membrane is past fixing.

Who made your system?

[GordMay]

The reverse osmosis membrane manufacturers warranty* is usually pro-rated over three years [extendable up to 5 years]; but expected lifetime can vary greatly, even, up to fifteen years.

* Dow Filmtec Warranty ➥ https://pureaqua.com/content/pdf/fil...t-warranty.pdf
Extension ➥ https://dupontwaterapp.com/en/tool/w...-certification

A good article:
The Life of a Reverse Osmosis Membrane, Part 1
➥ https://www.pumpsandsystems.com/life...embrane-part-1