RO Membrane Help

[Madreefer]

Looking to replace my membrane on Vertex Puratek will this membrane work?

http://www.jlaquatics.com/product/ro...29+Filter.html

[Reef Pilot]

Should work, if your unit came with a 100 gpd membrane. I am not familiar with that brand, though.

I know FilmTec (by Dow Chemical) are good quality, and very widely used be a lot of RO systems.
http://www.airwaterice.com/product/T...ne-100GPD.html

[mark]

over on RC some posts on the difference in a couple percent increase in rejection rate makes on ro life and little surprised (going from 96% to 98% can double your di life table here).

I was looking at this one http://www.reefsupplies.ca/online-st...ectrapure.html

[spit.fire]

Why not just get a vertex one? I'm picking one up on Tuesday

[Myka]

Since you're replacing your membrane, why not switch out the in line flow restrictor to either a 75 gpd or 150 gpd (if you have enough water pressure) and buy a matching membrane? The rejection rate on the 100 gpd membranes is terrible, and as mentioned, will affect your DI resin significantly Flow restrictors are like <$5.

[Madreefer]

Originally Posted by Myka

Since you're replacing your membrane, why not switch out the in line flow restrictor to either a 75 gpd or 150 gpd (if you have enough water pressure) and buy a matching membrane? The rejection rate on the 100 gpd membranes is terrible, and as mentioned, will affect your DI resin significantly Flow restrictors are like <$5.

It's already restricted down. I have the 200gpd unit.

[Madreefer]

Originally Posted by spit.fire

Why not just get a vertex one? I'm picking one up on Tuesday

I tried calling the store you work at today. No answer. Do you guys have all the filters instock for my unit? If you do I'll call tomoro and order them all.

[Madreefer]

Originally Posted by Madreefer

It's already restricted down. I have the 200gpd unit.

Oops my bad Mindy. I do have the 100gpd. Brain fart. I did have a restrictor in there before but I don't remember what it was. I believe I removed it. I will definitely be looking in to putting another one on there and thanks for posting that link Mark, that's good info. I'm thinking 50gpd if possible as I have a pretty big reservoir for RO water

[Myka]

Originally Posted by Madreefer

Oops my bad Mindy. I do have the 100gpd. Brain fart. I did have a restrictor in there before but I don't remember what it was. I believe I removed it. I will definitely be looking in to putting another one on there and thanks for posting that link Mark, that's good info. I'm thinking 50gpd if possible as I have a pretty big reservoir for RO water

You should have a restrictor in there to match whatever the combined flow of the membranes is. My system runs dual 150 gpd membranes so the restrictor is 300 gpd. The flow restrictor is what forces the water to go through the membrane. If you run the system without a restrictor, you will be causing lots of water to bypass the membrane and very little to actually be going through the membrane. Why would you remove the restrictor?

If anything, you can use a restrictor that is less than the combined flow of the membranes, but then you are causing the membrane to flush less than recommended. So say you have a membrane and system that run 1:4 ratio of good RO to waste. If you use a lesser restrictor then you may cause the system to run 1:2 or even 1:1. By preventing the flushing though, you can cause the membrane to prematurely clog up. So it depends which you prefer - membrane longevity or wasting less water.

[mark]

pressure and temperature effect the output from the membrane so if your not at the membranes specs, been reading using a 75gpd restrictor might not be the best match for a 75gpd membrane. Here talks about trimming the restrictor, can also use a variable restrictor for the change in temp with change in seasons to keep at the 4:1 waste ratio.