RODI Question about how long you get out of a membrane?

[FLSharkvictim]

I recently changed all my filters except for my membrane which was switched out about a year ago everything was just replaced two days ago.. I have a Sediment filter, two Carbon Filters, a DI and then the membrane.. I am getting a reading on my TDS monitor of 60 which is not good.. Zero Algae in the tank! Should I swap out the membrane even know its only been in there for a year or switch out the TDS METER? What are your thoughts?


Tank Info:
120 Mixed Reef
Ecotech M1 pump
Skimz 163 DC Montzer Series skimmer
Custom sump / Refuge
2 Maxspect Gyre XF130's Pumps
2 AI Hydra TwentySix HD LED Fixtures
Celestial C35W Maxspect Refuge Spotlight
Aqua UV Ultraviolet Sterilizer 25w
BRS Dual Media reactor
Eshoops IV Master doser & Slave
Tunze 3155 Auto Top Off

 

[mcgyvr]

They usually last ~3-5 years..
And you would typically base it on if its still meeting its specified rejection percentage.. which we can't help with as you only gave 1 number and you need to know what the supply (or pre RO) TDS is..
I'd replace when the rejection its not meeting its percentage (maybe within 5%).. flow will also be reduced.. I just do it every 3 years personally..

 

[FLSharkvictim]

My flow percentage is at 60% coming in from my house so i haven't lost any pressure. It has to be the membrane!! I am going to change out the membrane and install a new TDS meter as well.. Inline will be going before the DI and the outline will be installed after the DI. One I get every back up and running I will post a comment.


Out,
FLSharkvictim

 

[reeftivo]

you'll probably be fine with swapping the membrane. MAy want to look at the inline tds meter at BRS.
i've had no issues with my inline meter (2 years-same battery) and it was very affordable
http://www.bulkreefsupply.com/dual-...YCoMeA9xGOa4Rz__V0YqsGez9tUJruplHMaAoUH8P8HAQ

 

[Ou8me2]

I would definitely change the membrane. Really though you can't judge one membrane to the next. You have factors of source water TDS and I'd dare say that if you have very high TDS of 400-600+ you won't get as long out of it. Also if the membrane dry's out it ruins it also.

 

[LQT]

I have a Sediment filter, two Carbon Filters, a DI and then the membrane..

Just so we're clear, the order of flow for your RODI system is sediment filter, 2 carbon blocks then the RO membrane then into the DI stage, correct?

 

[mcgyvr]

My flow percentage is at 60% coming in from my house so i haven't lost any pressure.

What is the TDS of your tap water?
What is the TDS after the RO membrane?

 

[Buckeye Hydro]

I recently changed all my filters except for my membrane which was switched out about a year ago everything was just replaced two days ago.. I have a Sediment filter, two Carbon Filters, a DI and then the membrane.. I am getting a reading on my TDS monitor of 60 which is not good.. Zero Algae in the tank! Should I swap out the membrane even know its only been in there for a year or switch out the TDS METER? What are your thoughts?

Be happy to help you troubleshoot the system - feel free to give us a call when you are in front of your RODI.

To get our conversation started, we'll ask you:
1. What is your tapwater TDS?
2. What is your RO water TDS?
3. What is your DI water TDS?
4. What is your water pressure at the membrane when the system is running?

Someone we'll be manning the customer service lines all day today (Sunday).

Russ

 

[mpierce]

When are you taking the TDS reading? right after you turn on the unit, or are you waiting a few minutes? The TDS will always be high when you first turn it on.

 

[Buckeye Hydro]

When are you taking the TDS reading? right after you turn on the unit, or are you waiting a few minutes? The TDS will always be high when you first turn it on.

From two test runs with a Filmtec 75 gpd membrane. "Permeate" is another name for "RO water."

 

[Indymann99]

So this has me thinking... my RO system is 16yrs old. I have the original RO Membrane. I change out the dual carbon blocks every year.

I just went and checked readings and

Supply 322 TDS
Post membrane 6 TDS
Post dual DI 0 TDS

I have RO plumbed to 2 refrigerators for drinking water so it runs a fair amount. DI feeds the tank.

Buckeye Hydro, thoughts?

 

[Buckeye Hydro]

Your numbers say your membrane is doing what it should, even after 16 years, and your DI resin is still working as well.

To calculate your membrane's rejection rate:
322-6=316
316/322=0.98=98%

Do you have your RO water stream "split" with one leg feeding a pressurized tank and on the the refrigerators, and the other leg feeding your DI?

Russ

 

[Indymann99]

Thanks for the reply. Yes I have a pressure tank. I turn OFF valve to the pressure tank when I make RODI for the tank.

 

[Buckeye Hydro]

Thanks for the reply. Yes I have a pressure tank. I turn OFF valve to the pressure tank when I make RODI for the tank.

Perfect - or you can install a check valve if you don't want to mess around with closing the tank valve. Check out the diagram in the instructions for our Reef/Residential RODI here: http://www.buckeyehydro.com/instructions/

Russ