RO membrane efficiency of polyamide

[heintje23]

I got this claim from a distributor. It is for a TR70- 4040 HF membrane from ropur/toray. does anybody know if polyamide is better and 20% more efficient the filmtec for example. This membrane is 5 times the price of a filmtec.

"No, it's for seawater with a salt rejection over 99.6% on average, and Toray brand, manufactured in Spain and Germany. Use polyamide "S" that produces 20% more than the Filmtec. It is a membrane that has nothing to do with competition, is the best.
Of course it's more expensive."

[chrisjs]

So far as I can see from the specs. there is very lttle difference bwteen the salt water rejection versus Filmtec. Both Toray and Filmetc use polyamide film in their membranes. Certainly would not pay 5x more. Plus Filmtec are generally easily availbale at significant discount. You can afford to carry spares!! Biggest problem we had with our RO was prefilters plugging.

[Tellie]

Be careful what you are doing here, do you intend to use this watermaker in salt water? If so I'm not sure if you are aware of this but the TR70-4040 HF is a brackish water membrane not a salt water membrane. Big difference if you're going out in salt water.