How often do you have to replace your ro membrane?

ostrow · 01/19/2018, 07:56 PM

Please post system size and membrane size.

Me: 250g, 75gpd, and every 6 months. Something has to be wrong unless this is normal?

Psirex · 01/19/2018, 07:58 PM

Your RODI membrane? They last YEARS longer than 6 months

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300 gallon main 75 frag tank 55 gallon sump

120 gallon main 30 gallon sump (~ water volumn)

Psirex · 01/19/2018, 08:02 PM

How is your source water? What tells you it needs changing?

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lapin · 01/19/2018, 08:08 PM

On my old 125g, I had a 75gpd and membrane lasted 2 1/2 years. 15gal a week in evaporation. 60gal a month water changes. 280 TDS out of the tap.

ostrow · 01/19/2018, 08:14 PM

Yeah doesn't make sense. Chicago water. So ave 250 tds over a year.

Not overly bad. I don't get it.

Nobody faces a 6-mo change?

Psirex · 01/19/2018, 09:36 PM

My TDS at source gets as high as 250. I flush the membrane before EVERY use. When my product water starts to show TDS I replace my sediment filter and all is well...

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Dean Ladd · 01/19/2018, 09:50 PM

Agreed to realize the effective life of a RO Filter or any other filtration of the RO system you need a TDS meter. I am on well water my source TDS is 500. Out put with DI resin is 0. If my output reaches double digit TDS I will start seeing nuisance algae in the my DT. My RO filter has run for over 12 months. Everyones mileage may differ. Depends on how much RO water you use a day, week or year.

Quote:

Originally Posted by Psirex

My TDS at source gets as high as 250. I flush the membrane before EVERY use. When my product water starts to show TDS I replace my sediment filter and all is well...

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FNGsaltwater · 01/19/2018, 09:53 PM

I had to change mine every 6. Well, until I started draining it. My husband is certified in water treatment and he told me that it's because you make it too clean and it can't fight making a sludge in a nice dark pace of your membrane. My filters always looked fine but it slowed tremendously.

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ostrow · 01/19/2018, 10:14 PM

Quote:

Originally Posted by FNGsaltwater

I had to change mine every 6. Well, until I started draining it. My husband is certified in water treatment and he told me that it's because you make it too clean and it can't fight making a sludge in a nice dark pace of your membrane. My filters always looked fine but it slowed tremendously.

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Huh?

Let's be clear: this is NOT about DI (prior comments). And yes I have a dual inline tds. That's how I know membrane exhausted. 20+ tds out of membrane after 6mos.

I don't understand "draining it".

I have my ro on a solenoid to refill my top off reservoir every other day. There's no way to automate a flush. I flush it most days when I go in the fish room. But not before every use because I don't manually run my water...

galoot · 01/20/2018, 08:51 PM

What do you think is the "magic number" on the TDS meter to replace the RO membrane?

Just changed all my filters and DI resin. My tap water is reading 30ppm, RO water is currently reading no lower than 10ppm. I believe it used to by 1-2ppm when new.

I guess I'm answering my own question huh =) Prob time to change.

ostrow · 01/21/2018, 08:15 AM

Depends on the rejection rate of the membrane. Mine is 98%. So on 200tds water a tds of 10 is certainly bad.

FishTruck · 01/21/2018, 07:29 PM

This is critical.

Until I really understood my RO/DI system, I could never keep SPS. I live in Chicago. The water is very low TDS, but, something in it kills SPS but not LPS, fish, mammals, or inverts. Here is what you need to do:

1. Make sure your pre filter is changed every 6 months.
2. Run TWO stages of carbon before your RO, and change them every 6 months with your pre-filter.
3. Make sure your waste / product ratio is between 1:5 and 1:7. Down to 1:4 if you live in a Desert state.
4. Consider a pressure booster at the source.
5. Run an inline TDS monitor. My product is ZERO TDS. When it gets to 2 or 3 - go back to step 1.
5. Do not run your RO DI system directly to you Auto Top Off. The constant on off cycles screw up reverse osmosis membranes. I have a RO DI reservoir that I use both for top off and making new saltwater. It fills on a 12 hour timer into a 60 gallon vat, which reduces the on/off stress from the ATO.

ostrow · 01/21/2018, 08:00 PM

Yes I do all that and live on Chicago too.

Though, if you wait 6mos go change a sediment filter on chicago water you are waiting 4 months too long.

And 3 tds out of the di is way too high.

Still no clue why my membranes only last 3-6mos.

FishTruck · 01/22/2018, 07:52 PM

Quote:

Originally Posted by ostrow

Yes I do all that and live on Chicago too.

Though, if you wait 6mos go change a sediment filter on chicago water you are waiting 4 months too long.

And 3 tds out of the di is way too high.

Still no clue why my membranes only last 3-6mos.

True that... through trial and error, I can get away with 6 months. My RO membranes are going for 24 months now. Maybe... a new source of RO membranes??

flooddc · 01/22/2018, 08:21 PM

I think you have more responses if you post this in the filtration section!

3-6 months on a RO membrane seem abnormal. Typical membrane exhausted between 3-4 years. I normally replaced @ 3 years but had one that went way beyond because I got lazy (I made an average of 100-150G per/month).
Also, you mention that you have your RODI on a solenoid to refill your top-off everyday. I recalled reading somewhere that running your RODI daily in smaller volume also exhaust the membrane quicker vs running less often and making a large batch of water.

Oh! Check your waste line to see if any obstruction/blockage. Last year I had to replaced my membranes because my waste line was frozen (ran it to the outside during the winter month! duh!!).

ostrow · 01/22/2018, 09:53 PM

Topoff reservoir is every other day running 4 hrs.

I did check the waste. Running fine. Can't find an easy answer. Frustrating.

flooddc · 01/23/2018, 12:09 PM

I did a search and found a post a few years back that someone had a similar issue with the membrane exhausted quickly. Turned out, the membrane was not seated properly. Give it a shot. Good luck!

ostrow · 01/23/2018, 01:05 PM

Quote:

Originally Posted by flooddc

I did a search and found a post a few years back that someone had a similar issue with the membrane exhausted quickly. Turned out, the membrane was not seated properly. Give it a shot. Good luck!

I thought that after the first one went. But hard to believe that was an issue three times in a row now. I even tried a different housing.

flooddc · 01/23/2018, 01:37 PM

Man! don't know what else for you to try.
I see that you have been reefing for quite awhile. I assumed you use RODI system before and have no issue with the membrane or it's been like that from the beginning?

If you have been in the same place and have no issue before, maybe something is in the city water or they added something into the water facility that might cause the membrane to exhaust quickly. Maybe a shout-out to local reefers in your area to see if anyone else have similar issue. Good luck

ostrow · 01/23/2018, 03:09 PM

Yeah, this problem only started maybe 18mos (and 3-4 membranes) ago.

But Chicago water hasn't changed (I have checked). It's something system related not source related.

01/19/2018, 07:56 PM	#1
ostrow It's Dr. Goodluck Himself Join Date: Oct 2002 Location: Oak Park, IL Posts: 11,654	How often do you have to replace your ro membrane? Please post system size and membrane size. Me: 250g, 75gpd, and every 6 months. Something has to be wrong unless this is normal? __________________ It's the return of Dr. Goodluck Himself. fml! Current Tank Info: 156G "brick", 150 sump and 75 fuge replaces Fire, Destruction, Sad :(

01/19/2018, 07:58 PM	#2
Psirex Registered Member Join Date: Aug 2011 Location: Albany, NY Posts: 1,934	Your RODI membrane? They last YEARS longer than 6 months Sent from my SM-N950U using Tapatalk 300 gallon main 75 frag tank 55 gallon sump 120 gallon main 30 gallon sump (~ water volumn) __________________ SALINITY NOW....

01/19/2018, 08:02 PM	#3
Psirex Registered Member Join Date: Aug 2011 Location: Albany, NY Posts: 1,934	How is your source water? What tells you it needs changing? Sent from my SM-N950U using Tapatalk __________________ SALINITY NOW....

01/19/2018, 08:14 PM	#5
ostrow It's Dr. Goodluck Himself Join Date: Oct 2002 Location: Oak Park, IL Posts: 11,654	Yeah doesn't make sense. Chicago water. So ave 250 tds over a year. Not overly bad. I don't get it. Nobody faces a 6-mo change? __________________ It's the return of Dr. Goodluck Himself. fml! Current Tank Info: 156G "brick", 150 sump and 75 fuge replaces Fire, Destruction, Sad :(

01/19/2018, 09:36 PM	#6
Psirex Registered Member Join Date: Aug 2011 Location: Albany, NY Posts: 1,934	My TDS at source gets as high as 250. I flush the membrane before EVERY use. When my product water starts to show TDS I replace my sediment filter and all is well... Sent from my SM-N950U using Tapatalk __________________ SALINITY NOW....

01/19/2018, 08:08 PM	#4
lapin Registered Member Join Date: Aug 2017 Location: Austin Posts: 801	On my old 125g, I had a 75gpd and membrane lasted 2 1/2 years. 15gal a week in evaporation. 60gal a month water changes. 280 TDS out of the tap.

01/19/2018, 09:53 PM	#8
FNGsaltwater Registered Member Join Date: Nov 2016 Posts: 116	I had to change mine every 6. Well, until I started draining it. My husband is certified in water treatment and he told me that it's because you make it too clean and it can't fight making a sludge in a nice dark pace of your membrane. My filters always looked fine but it slowed tremendously. Sent from my LG-H872 using Tapatalk

01/20/2018, 08:51 PM	#10
galoot Registered Member Join Date: Dec 2007 Location: San Carlos Posts: 559	What do you think is the "magic number" on the TDS meter to replace the RO membrane? Just changed all my filters and DI resin. My tap water is reading 30ppm, RO water is currently reading no lower than 10ppm. I believe it used to by 1-2ppm when new. I guess I'm answering my own question huh =) Prob time to change. Last edited by galoot; 01/20/2018 at 09:13 PM.

01/21/2018, 08:15 AM	#11
ostrow It's Dr. Goodluck Himself Join Date: Oct 2002 Location: Oak Park, IL Posts: 11,654	Depends on the rejection rate of the membrane. Mine is 98%. So on 200tds water a tds of 10 is certainly bad. __________________ It's the return of Dr. Goodluck Himself. fml! Current Tank Info: 156G "brick", 150 sump and 75 fuge replaces Fire, Destruction, Sad :(

01/21/2018, 07:29 PM	#12
FishTruck Premium Member Join Date: Jul 2007 Location: Downers Grove, IL Posts: 805	This is critical. Until I really understood my RO/DI system, I could never keep SPS. I live in Chicago. The water is very low TDS, but, something in it kills SPS but not LPS, fish, mammals, or inverts. Here is what you need to do: 1. Make sure your pre filter is changed every 6 months. 2. Run TWO stages of carbon before your RO, and change them every 6 months with your pre-filter. 3. Make sure your waste / product ratio is between 1:5 and 1:7. Down to 1:4 if you live in a Desert state. 4. Consider a pressure booster at the source. 5. Run an inline TDS monitor. My product is ZERO TDS. When it gets to 2 or 3 - go back to step 1. 5. Do not run your RO DI system directly to you Auto Top Off. The constant on off cycles screw up reverse osmosis membranes. I have a RO DI reservoir that I use both for top off and making new saltwater. It fills on a 12 hour timer into a 60 gallon vat, which reduces the on/off stress from the ATO. __________________ Department of Redundancy Department. Current Tank Info: Established 2009 - 300 gal acrylic mostly sps, radion LEDs

01/21/2018, 08:00 PM	#13
ostrow It's Dr. Goodluck Himself Join Date: Oct 2002 Location: Oak Park, IL Posts: 11,654	Yes I do all that and live on Chicago too. Though, if you wait 6mos go change a sediment filter on chicago water you are waiting 4 months too long. And 3 tds out of the di is way too high. Still no clue why my membranes only last 3-6mos. __________________ It's the return of Dr. Goodluck Himself. fml! Current Tank Info: 156G "brick", 150 sump and 75 fuge replaces Fire, Destruction, Sad :(

01/22/2018, 08:21 PM	#15
flooddc Registered Member Join Date: May 2012 Location: Maryland Posts: 304	I think you have more responses if you post this in the filtration section! 3-6 months on a RO membrane seem abnormal. Typical membrane exhausted between 3-4 years. I normally replaced @ 3 years but had one that went way beyond because I got lazy (I made an average of 100-150G per/month). Also, you mention that you have your RODI on a solenoid to refill your top-off everyday. I recalled reading somewhere that running your RODI daily in smaller volume also exhaust the membrane quicker vs running less often and making a large batch of water. Oh! Check your waste line to see if any obstruction/blockage. Last year I had to replaced my membranes because my waste line was frozen (ran it to the outside during the winter month! duh!!).

01/22/2018, 09:53 PM	#16
ostrow It's Dr. Goodluck Himself Join Date: Oct 2002 Location: Oak Park, IL Posts: 11,654	Topoff reservoir is every other day running 4 hrs. I did check the waste. Running fine. Can't find an easy answer. Frustrating. __________________ It's the return of Dr. Goodluck Himself. fml! Current Tank Info: 156G "brick", 150 sump and 75 fuge replaces Fire, Destruction, Sad :(

01/23/2018, 12:09 PM	#17
flooddc Registered Member Join Date: May 2012 Location: Maryland Posts: 304	I did a search and found a post a few years back that someone had a similar issue with the membrane exhausted quickly. Turned out, the membrane was not seated properly. Give it a shot. Good luck!

01/23/2018, 01:37 PM	#19
flooddc Registered Member Join Date: May 2012 Location: Maryland Posts: 304	Man! don't know what else for you to try. I see that you have been reefing for quite awhile. I assumed you use RODI system before and have no issue with the membrane or it's been like that from the beginning? If you have been in the same place and have no issue before, maybe something is in the city water or they added something into the water facility that might cause the membrane to exhaust quickly. Maybe a shout-out to local reefers in your area to see if anyone else have similar issue. Good luck

01/23/2018, 03:09 PM	#20
ostrow It's Dr. Goodluck Himself Join Date: Oct 2002 Location: Oak Park, IL Posts: 11,654	Yeah, this problem only started maybe 18mos (and 3-4 membranes) ago. But Chicago water hasn't changed (I have checked). It's something system related not source related. __________________ It's the return of Dr. Goodluck Himself. fml! Current Tank Info: 156G "brick", 150 sump and 75 fuge replaces Fire, Destruction, Sad :(