PDA

View Full Version : RO Membrane?


jfingers8
07/08/2010, 07:59 PM
I need to replace my membrane on my ro unit. It's rated for 50 gpd. 2 questions one, does it matter if I buy one that is rated more or less than 50 gpd and two, does it matter what company I go with or is a membrane a membrane? Thanks

Eel Freak
07/08/2010, 09:17 PM
1) you should be fine getting any membrane, but make sure it will fit in your membrane housing. If you're RO unit is nothing custom, and you don't go out on a limb trying to find some giant membrane, you'll be fine.

2) an RO membrane is an RO membrane. So long as it's the same physical dimensions, it shouldn't matter.

jfingers8
07/08/2010, 10:16 PM
thank you

Toddrtrex
07/08/2010, 10:42 PM
Not all RO membranes are the same. I personally only use the Dow Filmtec 75 GPD one -- it has a rejection rate of 96-98%, whereas other ones -- a lot of the 50 GPD ones will be around 90% -- the difference will extend the life of your DI resin.

If you do switch to a 75 GPD one, make sure to switch out the flow restritor.

Dave VG
07/09/2010, 04:44 AM
If you do switch to a 75 GPD one, make sure to switch out the flow restritor.

Toddrtrex makes a very good point. You can’t just throw any membrane in there. Flow rate makes a big difference in different flow rated membranes as far as rejection rate. But as Toddrtrex said change the flow restrictor and you should be fine.

Eel Freak
07/09/2010, 04:58 AM
If you do switch to a 75 GPD one, make sure to switch out the flow restritor.

Yes, definitely. I forgot to mention that.

My personal vote is the DOW/Filmtec 75GPD membrane. It has excellent performance and as stated before, won't eat up your DI resin as fast as some other membranes.