Rodi
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luke33
2500 Club Member
Depends on your tds #'s and how much water you make. I use the normal 100gpd filmtec membrane, and pry make 30-35g per week with a tds of 450. Generally i replace mine once a year. Its going to be diff for everyone. If my tds were only 100 could be once every year and a half.
melev
Avid Hobbyist
Where I live, TDS is around 170 out of the faucet. The membrane in my RO/DI lasted just over 5 years.
The filters including the DI cartridge had to be changed out every 5 months to maintain 0 TDS water.
Then I upgraded to a new RO/DI system with a booster pump last August. With the increased pressure, the membrane has been more efficient and the waste water decreased. I'm still using the same DI cartridge I used a year ago, because the TDS coming out of the membrane measures 1. It was so worth it upgrading.
I probably make between 200 and 250g of water each month.
There are a number of factors that determine how long a membrane will last, and that is why most manufacturers will state membranes last 1-5 years. For some, their water is horrible and the membrane only lasts 12 months. Others can use theirs for years. Changing filters on a regular basis protects the membrane from damage (by chlorine), and by avoiding TDS creep hobbyists are able to make their DI resin last longer too. Reef Addicts - RO/DI TDS Creep - is it worthy of concern?
The filters including the DI cartridge had to be changed out every 5 months to maintain 0 TDS water.
Then I upgraded to a new RO/DI system with a booster pump last August. With the increased pressure, the membrane has been more efficient and the waste water decreased. I'm still using the same DI cartridge I used a year ago, because the TDS coming out of the membrane measures 1. It was so worth it upgrading.
I probably make between 200 and 250g of water each month.There are a number of factors that determine how long a membrane will last, and that is why most manufacturers will state membranes last 1-5 years. For some, their water is horrible and the membrane only lasts 12 months. Others can use theirs for years. Changing filters on a regular basis protects the membrane from damage (by chlorine), and by avoiding TDS creep hobbyists are able to make their DI resin last longer too. Reef Addicts - RO/DI TDS Creep - is it worthy of concern?
iReefer
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just got about 50g out of it but the tds read 38ppm after DI.
Before DI was 40 ppm.
and the DI resin is new too. (from aquaticlife)
what i should i do? sorry dont know much about RODI. lol always been purchasing water from the lfs.
Before DI was 40 ppm.
and the DI resin is new too. (from aquaticlife)
what i should i do? sorry dont know much about RODI. lol always been purchasing water from the lfs.
KingRicky
Well-Known Member
How old is the membrane? I would think that the post membrane should be less than 40, so I would say you need to change it out. My pre-membrane water is 350, post membrane is 2, and post DI is 0.
condor
CORAL DR.
if the membrane ever dried out,or got hot its done. but if your tds meter is calibrated correctly and you get 38ppm then i would say replace the membrane. and in the future dont let the sediment and carbon get near clogged. stay on top of replacing those and your membrane will last longer
condor
CORAL DR.
yeah ive always used valuetrex sediment and omnipure carbon blocks. perform great for me
The life of the membrane depends on several things. A high quality, low micron prefilter and carbon block are at the top of the list, their sole purpose is to protect the membrane so it can do its job of removing TDS. One item often overlooked though is the waste ratio of the unit. Many vendors, resellers and manufacturers often include non adjustable type flow restrictors which is a lousy idea since we all know our water conditions are not all the same. Many restrictors are mis sized so you either waste too much causing a pressure drop at the membrane leading to lower production and lower efficiency or they do not waste enough which gives the membrane more pressure and higher efficiency but sacrificing the membranes lifespan. A capillary tube type flow restrictor you take the time to trim for your exact water conditions is about $5.
Everyone needs to check their waste ratio time to time to ensure it is at least 3.5:1 and prefferably 4:1 to keep the membrane flushed and fresh.
Other factors are your usage patterns, long filter runs are far better than short spurts so the membrane gets a chance to flush itself. Colder water actually treats better than warm water and any water over 113 degrees will melt a membrane in a heartbeat. Water pressure is also a big factor as Melev stated, membranes like pressure, up to 100 psi is great and its really the housings and fittings that are the limiting factor as the membarne can go much higher than that. I run my booster at 100 psi always.
Don't just buy name brand filters, make sure they are the correct micron ranges too, a 10 micron prefilter may be as effective as a screen door when it comes to particulates and colloidal materials causing the carbon block to foul or plug which in turn passes chlorine on to the RO membrane melting it in a matter of days.
When I used the Typhoon III standard filters I could only get 18 months out of a membrane.
Once I wised up and went to lower micron, absolute rated filters my membranes are still fresh after 3 years and I fully expect 7-10 years of heavy use with no degredation here in Phoenix with a tap TDS over 800 most of te time. My RO only TDS is 5-6 and thats a 99.35% rejection rate still after three years on the present system. Randy Holmes Farley recently reported 10 years out of the same membrane by using high quality filters and replacing them as recommended.
Just because you just purchased the resin does not mean it is fresh. Many companies sell resin tha thas been sitting on a shelf somewhere and even properly vacuum packed damp resin has a shelf life of about 6 months when kept sealed in the refrigerator.
If your RO only TDS is 40 then you definitely have membrane issues. If the DI is still 38 then its not doing anything either. A good membrane should give you 96-98% rejection or removal efficiency at the proper pressure and water temperature.
Everyone needs to check their waste ratio time to time to ensure it is at least 3.5:1 and prefferably 4:1 to keep the membrane flushed and fresh.
Other factors are your usage patterns, long filter runs are far better than short spurts so the membrane gets a chance to flush itself. Colder water actually treats better than warm water and any water over 113 degrees will melt a membrane in a heartbeat. Water pressure is also a big factor as Melev stated, membranes like pressure, up to 100 psi is great and its really the housings and fittings that are the limiting factor as the membarne can go much higher than that. I run my booster at 100 psi always.
Don't just buy name brand filters, make sure they are the correct micron ranges too, a 10 micron prefilter may be as effective as a screen door when it comes to particulates and colloidal materials causing the carbon block to foul or plug which in turn passes chlorine on to the RO membrane melting it in a matter of days.
When I used the Typhoon III standard filters I could only get 18 months out of a membrane.
Once I wised up and went to lower micron, absolute rated filters my membranes are still fresh after 3 years and I fully expect 7-10 years of heavy use with no degredation here in Phoenix with a tap TDS over 800 most of te time. My RO only TDS is 5-6 and thats a 99.35% rejection rate still after three years on the present system. Randy Holmes Farley recently reported 10 years out of the same membrane by using high quality filters and replacing them as recommended.
Just because you just purchased the resin does not mean it is fresh. Many companies sell resin tha thas been sitting on a shelf somewhere and even properly vacuum packed damp resin has a shelf life of about 6 months when kept sealed in the refrigerator.
If your RO only TDS is 40 then you definitely have membrane issues. If the DI is still 38 then its not doing anything either. A good membrane should give you 96-98% rejection or removal efficiency at the proper pressure and water temperature.
melev
Avid Hobbyist
Where's the DI? Is it the one on the far left? If so, it is plumbed incorrectly. It looks like the water from the carbon is going to the DI, and the from the DI to the membrane on top. If that is the case, the DI is already wiped out. It needs to come after the membrane, after the maximum amount of TDS was extracted by the membrane.
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iReefer
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the far right is the Di with the blue valve and blck tube (on the last pix). and it is after the membrane.
it is weird. Do you think may be the DI was defected ? it is aquatic life refillable DI with 1 time resin in it already when i bought it. Maybe the resin is expired? should it be the case
it is weird. Do you think may be the DI was defected ? it is aquatic life refillable DI with 1 time resin in it already when i bought it. Maybe the resin is expired? should it be the case
melev
Avid Hobbyist
We need more pictures. I would swear that I see a slight orange tint of the left filter as if it was DI resin up 2/3 full. DI resin (even unopened) can go bad if it sits around too long, or sits in a hot warehouse / garage.
