rodi membrane replacement

saixiong08 · Oct 31, 2015

http://www.fountainheadwatersystems.com/6stagerodicore.htm

i currently have this unit, how would i go upon replacing the membrane, and where would i be able to purchase it?

twilliard · Oct 31, 2015

@AZDesertRat
Thanks!
Its easy to replace if its a standard membrane then spectrapure is a good start or the filter guys here on R2R

saixiong08 · Oct 31, 2015

thanks what about the color changing di in clear refillable inline housing? where can i get those and how often do i need to change/replace them

Randy Holmes-Farley · Oct 31, 2015

How do you know you need to change the membrane?

If you have not yet replaced the DI resin, you shouldn't need to replace the membrane unless you bought a used unit.

AZDesertRat · Oct 31, 2015

As Randy mentioned, your membrane may not need replacement. What are your tap water TDS, RO only TDS and final RO/DI TDS readings?

Membranes should last years if taken care of and your water hardness isn't through the roof.

ReeferBob · Nov 2, 2015

You need to get a TDS meter (or two). I have 2 dual meters. I have a probe connected right after the 1st filter, before and after the membrane and coming out of the DI resin. Use the TDS numbers to see when your filters need replacing.

Mark_D · Nov 3, 2015

kind of the same topic... We just replaced our Culligan water filter system and was wondering if I could still use the old setup for my aquarium? It was for drinking water, but can I or do I need to add another filter to use it for an aquarium?

Randy Holmes-Farley · Nov 3, 2015

Can you describe what filters it contains?

At the least, you likely want to add a DI as the last filter.

Mark_D · Nov 3, 2015

I'll take a picture of what I presently have tonight and post as soon as I have them

Mark_D · Nov 4, 2015

This is what we were using...

AZDesertRat · Nov 4, 2015

Before you use what you have for reef water I would first determine how well it is working. You need a handheld TDS meter to determine your tap wter TDS and your RO only water TDS. Don't use the pressure tank or the little inline taste and odor carbon filter as they will both add TDS back to the treated water, you want to test directly from the RO membrane. Depending on your tap water TDS, I would not use the RO if the rejection rate or removal efficiency is not better than 96% or so. What you will find is it will go through DI resin very quickly if you make much RO/DI water.

If it were me, I would keep the booster pump and buy a new reef quality RO/DI or better yet, install a tee and check valve directly off the RO membrane with your new system and install a DI filter there. The check valve would isolate the DI filter from the TDS creep water in the drinking water pressure tank and in tha tway you can use one system for both needs.
Take a look at this diagram. Note the placement of the tee can check valve between the RO and the DI so you get pressurized drinking water as well as being able to make DI water for the reef.
http://spectrapure.com/huds/4-STAGE-DWK-RODI-AG.pdf

Mark_D · Nov 5, 2015

thank you so much for that diagram. That makes sense. I think I might ditch the idea of using the old setup and get a new unit. Branching off the new setup would be a little more difficult since it's a Kinetico system

pipes · Nov 5, 2015

An R.O. system is an R.O. system. If you go online BRS has the D.I. housings that you can add to your R.O. Just check with your Kinetico dealer re: warenty. All you would have to do is tee off of your tap line, install a valve and run to the D.I. canisters. Some people don't even use the D.I. D.I. just means that the water has a lower T.D.S. If you want to use the "crappy"( it's okay I use to work for them) Culligan system make sure you have pre-filtration( at least a 5 micron sediment cartridge and a carbon cartridge) before the membrane. Trust me you don't want to pay the big C for a new membrane. Easily double the price it should be. Culligan is like Harley Davidson....Just paying for the name.

AZDesertRat · Nov 5, 2015

An RO system is not an RO system, just like everything else there are good and not so good. Just because one looks like another does not mean it is the same quality nor perform as well. Add DI to an inefficient membrane and you eat resin like crazy, driving the operating cost up. Add DI to a good membrane and it could last a year or more.

You don't add the DI to the tap line, you add it after the RO membrane. RO is intended as pretreatment for DI and should do 90-98+% of the treatment with the DI taking up the slack. RO/DI water should have 0 TDS, not just lower TDS. Good RO/DI is 18.2 megaohms resistivity or about as pure as it comes and electrically non conductive.