Picking RO Membrane

[dragonfisher33]

My RODI filter needs a RO membrane replacement.

This is my RODI filter
Amazon.com : Coralife 05692 Pure-Flo II 50-Gallon Per Day 4 Stage RO/DI System : Aquariums : Pet Supplies

When picking out the RO membrane replacement, what are these little nuances on the naming between the 75GPD, 100GPD and 50GPD?

[h=2]Filmtec BW60-1812-75 75 GPD Filmtec Residential RO Membrane[/h][h=2]Filmtec TW30-1812-100 100 GPD Filmtec Residential RO Membrane[/h][h=2]Filmtec TW30-1812-50 TFC Membrane, 1-Pack[/h]
What's the difference between BW60 vs TW30? Which one will fit my RODI filter? of course i can go with the 50GPD membrane but would prefer to go up a bit in the water production.

 

[AZDesertRat]

Forget the 100 GPD completely, it is only a 90% rejection rate nano filter and not a true 96-98% rejection rate Reverse Osmosis membrane. Any good vendor will do their best to talk you out of it for a reef RO or RO/DI, it is designed for drinking water or more accurately "Pool and Spa use" per the ANSI/NSF.

I believe the BW is a typo and the only difference between the 50 and the 75 are the GPD's.

If it were me I would pass on all of them and go for a more efficient RO membrane so you save money on DI replacements. For every 2% you can improve on that 90, 96 or 98% rejection rate you will double your DI life so the beter membrane quickly pays for itself.

This membrane starts out life as a 75GPD Dow Filmtec but is subjected to a proprietary process which improves it efficiency then batch tested for quality control and shipped wet in a special solution. The others you showed are shipped dry, untested and you get what you get.
Standard 90-GPD RO Membrane

This membrane also starts out as a 75 GPD Dow Filmtec and goes through the same treatment process but each one is individually hand tested and guaranteed to be 99% rejection rate or better in writing. This is the membrane I use personally and it has averaged 99.4% efficiency for about 7 years now and still going strong. The money it has saved in DI replacements is in the hundreds of dollars and it paid for itself in the first year alone.
SpectraSelect PlusC 90-GPD RO 99 Percent Rejection Membrane

With any membrane replacement make sure you also replace the flow restrictor with one matched to the membrane such as here so you maintain the correct waste ratio for your water conditions.
Flow Restrictor - Standard - 90-GPD
Flow Restrictor - Preset-Red (Hard Water) - 90-GPD
Flow Restrictor - Preset-Green (Soft Water) - 100-GPD

 

[cdness]

I couldn't have said it better myself! I also switched from the BRS 75 GPD membrane to the Spectrapure 90 GPD and will never look back.

 

[Opus]

I second the spectrapure membrane. If you can wait until next month you might be able to save a few bucks. I'm sure there will be some sales for Presidents day. I picked up mine during a 10% sale at Premium Aquactics last year and also got some filters since everything was 10% off. I usually try and hold off for one of their sales and then buy enough stuff to get to their free shipping amount.

 

[BBoley24]

OK so I have an aquafx 100gpd RODI unit.

I need a membrane.

You're advising that I should get the spectrapure 90gpd w a new restrictor.

That's all I need to modify my RODI to maximum potential?