I brought my membrane to my LFS and its leaking .4 ppm phosphates and probably god knows what else. The things only a year old, but I was supposed to change the 3 prefilters after 6 months, I just recently changed them. Would that 6 months of bad prefilters be the cause for the membrane failing?
RO/DI unit leaking phosphates
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AZDesertRat
In Memoriam
No, prefilters and carbons have no effect on phosphates.
To tackle phosphates you need a good 98% efficient RO membrane, not a 90% 100GPD nanofilter and a good vertical 24oz large capacity DI filter, not a small 6 or 12oz capacity horizontal one. It takes the combination of both to work best.
Always change prefilters and carbons at 6 month intervals and remember to disinfect the housings before installing new filters.
To tackle phosphates you need a good 98% efficient RO membrane, not a 90% 100GPD nanofilter and a good vertical 24oz large capacity DI filter, not a small 6 or 12oz capacity horizontal one. It takes the combination of both to work best.
Always change prefilters and carbons at 6 month intervals and remember to disinfect the housings before installing new filters.
So, even if the prefilters were shot, it wouldn't destroy the membrane?
I never checked the phosphates really, but the tank has always done amazing (since I started doing regular water changes), I haven't seen hair algae in about 9 months. I would always keep it saturated in the membrane housing. I would flush the system only when I remembered to do it though. (Iv done it may 3 times in the past year:eek1: ). But apparently you can only store it in the filter if you are going to use it again within the next 30 days.(which I am almost positive I didn't do in more than a few months) Also, is it ok to keep water in the system? I keep water in all 3 prefilters since I got it, and let it sit idle for a week or 2. I am still using the DI cartridge that came with the unit because I figured, only half the resin changed color, so why change it, then I read the RO/DI faq and it says to change it every 6 months anyway...
Its a Pure-Flo II RO Unit - 50 GPD TFC - 3 Canister
AZDesertRat
In Memoriam
The only way to tell if the membrane is shot is with a TDS or conductivity meter. This is also the only way to tell if the DI is any good which I suspect it is not.
A worn out prefilter would normally be plugged or at least reduce the pressure available to the membrane causing low production. A worn out carbon filter can do serious damage to a membrane. Carbon adsorbs chlorine which can destroy a membrane in a hearbeat. Less expensive carbon blocks or worse yet granular activated carbon only has the capacity to adsorb anywhere from a few hundred gallons of chlorine at 1 ppm to maybe a few thousand at most. Good carbon blocks can adsorb 20,000 gallons worth. The only way to tell if carbon is exhausted is with a low range chlorine test kit, if any CL2 is detected after the carbon or membrane its shot and possibly/probably the membrane too.
The best method is use only high quality filters, change the filters at 6 month intervals, disinfect the unit when changing filters and use a TDS meter every time you make DI water.
DI has a specific capacity it will filter and color changing resin is an extremely poor indicator of resin condition, I won't even use it myself. Get a TDS meter and use it on a regular basis.
A worn out prefilter would normally be plugged or at least reduce the pressure available to the membrane causing low production. A worn out carbon filter can do serious damage to a membrane. Carbon adsorbs chlorine which can destroy a membrane in a hearbeat. Less expensive carbon blocks or worse yet granular activated carbon only has the capacity to adsorb anywhere from a few hundred gallons of chlorine at 1 ppm to maybe a few thousand at most. Good carbon blocks can adsorb 20,000 gallons worth. The only way to tell if carbon is exhausted is with a low range chlorine test kit, if any CL2 is detected after the carbon or membrane its shot and possibly/probably the membrane too.
The best method is use only high quality filters, change the filters at 6 month intervals, disinfect the unit when changing filters and use a TDS meter every time you make DI water.
DI has a specific capacity it will filter and color changing resin is an extremely poor indicator of resin condition, I won't even use it myself. Get a TDS meter and use it on a regular basis.
africangrey
Active member
What do you mean by disinfect the housing, and do you do that why is that important, thanks for elaborating.
AZDesertRat
In Memoriam
It had to come through the filter to get into the holding tank so that makes no sense.
Disinfection is very important and even critical if you or your pets consume any of the water. Housings and filters can be a breeding ground for bacteria and viruses as well as algaes if not maintained properly. Remember, once you pass water through the first carbon filter there is no disinfectant present anymore. Water sits in the housings for days or weeks on end and sometimes in extreme temperatures with bright lighting or even sunlight shining on the clear housings. You have just provided everything they need to grow and multiply.
By disinfecting the housings every 6 months when you change the filters you greatly reduce the odds of this happening. All RO and RO/DI suppliers should provide clear directions on how to do this procedure which only takes a few extra minutes if done when the housings are already empty for changes.
Disinfection is very important and even critical if you or your pets consume any of the water. Housings and filters can be a breeding ground for bacteria and viruses as well as algaes if not maintained properly. Remember, once you pass water through the first carbon filter there is no disinfectant present anymore. Water sits in the housings for days or weeks on end and sometimes in extreme temperatures with bright lighting or even sunlight shining on the clear housings. You have just provided everything they need to grow and multiply.
By disinfecting the housings every 6 months when you change the filters you greatly reduce the odds of this happening. All RO and RO/DI suppliers should provide clear directions on how to do this procedure which only takes a few extra minutes if done when the housings are already empty for changes.
africangrey
Active member
I don't think airwaterice's manual provides any instruction, can we just bleach it and rinse with water afterwards.
Hope fish and coral can tolerate trace of bleach, but I guess RO and DI should be able to take care of the residue.
Hope fish and coral can tolerate trace of bleach, but I guess RO and DI should be able to take care of the residue.
AZDesertRat
In Memoriam
My disinfection method when replacing the prefilter and carbon block but not the membrane is:
1. Shut off the incoming water.
2. Disconnect the line which goes from the carbon block up to the RO membrane at the membrane housing. (Very Important)
3. Unscrew the prefilter and carbon block housings and remove the old filters. Screw the empty carbon housing(s) back on hand tight.
4. Place 2 or 3 teaspoons (no more than that) of regular unscented bleach in the prefilter housing and reinstall the empty housing.
5. Turn the water back on and catch the water from the 1/4" tube you removed in a bucket or in the sink. Continue to flush until there is no trace of chlorine odor.
6. Unscrew the housings, dump the water, install the new filter cartridges and reinstall the housings. Open the incoming water and fill the housings until water comes out the 1/4" tube. Reinsert the tube and you are up and running for another 6 months.
Don't over do it on the bleach! Household bleach is about 5% strength when new which equals 50,000 parts per million so it goes a long way. It only takes about 1 part per million to kill just about any virus of bacteria.
1. Shut off the incoming water.
2. Disconnect the line which goes from the carbon block up to the RO membrane at the membrane housing. (Very Important)
3. Unscrew the prefilter and carbon block housings and remove the old filters. Screw the empty carbon housing(s) back on hand tight.
4. Place 2 or 3 teaspoons (no more than that) of regular unscented bleach in the prefilter housing and reinstall the empty housing.
5. Turn the water back on and catch the water from the 1/4" tube you removed in a bucket or in the sink. Continue to flush until there is no trace of chlorine odor.
6. Unscrew the housings, dump the water, install the new filter cartridges and reinstall the housings. Open the incoming water and fill the housings until water comes out the 1/4" tube. Reinsert the tube and you are up and running for another 6 months.
Don't over do it on the bleach! Household bleach is about 5% strength when new which equals 50,000 parts per million so it goes a long way. It only takes about 1 part per million to kill just about any virus of bacteria.
Will the carbon in the prefilter get used up if water is left in there when its sitting idle?
I have no idea what type of tds meter to purchase. I want an accurate one that won't put a hole in my pocket. And they need calibration fluid and all that crap. Id be willing to spend about $60 max for one. Any suggestions?
I have no idea what type of tds meter to purchase. I want an accurate one that won't put a hole in my pocket. And they need calibration fluid and all that crap. Id be willing to spend about $60 max for one. Any suggestions?
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AZDesertRat
In Memoriam
The only TDS meter I would consider is the HM Digital COM-100. Its 10x more accurate than any other hobbyist meter on the market since it can be calibrated in several different modes. It can also be used as a true conductivity meter too.
Inlines are OK as guides only as they are not truly temperature compensated. Unless your water temp and air temp are exactly the same they will be inaccurate since they sense air temp only.
As long as it does not have water running to waste all the time your carbon will not be doing anything and will not be depleted. The water sitting in the canister has already had the chlorine and VOCs adsorbed when it first entered so it is not doing any further work.
Inlines are OK as guides only as they are not truly temperature compensated. Unless your water temp and air temp are exactly the same they will be inaccurate since they sense air temp only.
As long as it does not have water running to waste all the time your carbon will not be doing anything and will not be depleted. The water sitting in the canister has already had the chlorine and VOCs adsorbed when it first entered so it is not doing any further work.
