DI resin exhausted fast with a tds of 3-4 going in

[chilwil84]

My DI resins gets exhausted fast even with a real low tds 3-4. i read that it may be due to high amounts of C02 in my well water. Is there anyway to lower the C02 without having to let the water sit for a period of time.

[redfishblewfish]

Carbon Dioxide in well water is a common problem. Not a bit surprised. The easiest (and cheapest) way to do this is to run RO water into a container, bubble the water overnight, and then pump it through the DI resin. Don’t know the volume of water you are making per day, but with some well water, you can easily go through a canister of DI in a day. You can treat chemically, but now you’ll be replacing that compound. One way is to treat with limewater….talk to a water treatment company on what you would need to install for home use.

[bennr]

You are putting well water through a RODI filtration system??? lol

[redfishblewfish]

Am I missing something?


Many “city” water systems use wells. Just because it comes from a well doesn’t mean it is “clean” water. So I’m not sure what’s so funny. Someone help me with this one.

[greg0385]

Found this out the hard way too. I have 16tds out of the faucet an 4tds coming out the ro membrane and i can only make bout 60-90 gallons of good water before the di resin is exhausted. So now i filled up a 32gallon trashcan from out of the membrane and have a bubble wand in the bottom. Going to buy more di resin and pump the airated water into the di chamber to see the new results. Sad thing is im 30 gallons short from filling my new 200 gallon tank and no di resin here to finish filling it this weekend.

[redfishblewfish]

Greg, regenerate the DI resin. It's pretty easy:

http://www.reefkeeping.com/issues/20...nftt/index.php

[greg0385]

That makes me nervous and i only have two canisters of exhausted at amount. Maybe when i have alot to do at once

[chilwil84]

i have my ro unit set up on a line that bypasses my acid neutralizer system(i have super low ph ie soft water) i wonder if i run it off the normal house line if it would be any better.

[tkeracer619]

Originally Posted by bennr

You are putting well water through a RODI filtration system??? lol

Whats so funny? (in my best tough guy accent)

[bennr]

there is a difference between actual well water straight from the ground and city well water.....well water (not city well) has been known to damage many components in anything using it....what sort of filtration do you have for your well when it enters the house?? or are you on city or town well??

[chilwil84]

my own private well. the house is filtered by a acid neutralizer to raise the ph of the water. i live on the edge of the pine barrens in south jersey and most of the ground water is very acidic but low in minerals (ie no iron or other metals that people use salt to remove)

[bennr]

do you know what the ph is of your water straight from the well?? and after the neutrslizer?? i do not believe this would be the issue. my one buddy drills wells for a living and last night told me that carbon dioxide can be a problem in wells.....only way to know if you do have too much c02 is to test it he said but that would require the proper equipment. he slso said he would recommend you put water through the neutralizer and then into the rodi. try putting water through the neutralizer and then let it sit for a bit and stir it often....he said they do make equipment to remove c02 from well water...hope this will help. what are your tds readings before the neutralizer and then after the neutralizer?? i can see that it is 3 - 4 after ro before di.....which is what mine is right now...i am thinking of changing my ro membrane tho soon because when it is new i can get 0ppm out of ro alone before di.....the guy i bought my rodi off is a dealer and he said ro membrane should be changed when it reaches 4-5ppm....i might as well do my other filters too. I am two years on my membrane so i guess it might be time lol. How old is your membrane??

[Buckeye Hydro]

Bennr - need a little more information to advise you well.

What is the TDS of your tap water?
What is the water pressure reaching the membrane?
What is the capacity (in gallons per day) of your membrane?
What is the TDS of your RO (not DI) water?

Russ

[greg0385]

Well i dont know bout his but mine is 40psi. Its 75gpd membrane. It makes 4cups of bad to a little over a cup of good. Feed water tds is 16-22 and after the membrane its 4-6tds. I only get 60-90 gallons of good water before my di is exhausted. I think mine is co2 and trying the bubble wand in a contsiner before the di chamber. Only problem is im out of di resin and have to wait.

[bennr]

My tap water is 118ppm ..... not too sure what the water pressure into the membrane would be.....i just have it hooked up to the street water pressure and then it goes through the first 3 prefilters (5 micron, carbon, 1 micron) and then into the ro membrane and then into the post carbon.....it will store this water in the small tank and then push it rhru the di media whenever i turn the valve.....so i am not really too sure what the pressure is when it gets to the membrane....but i know that my water is currently testing 4ppm from just ro alone.....used to test 0 (rarely 1) but has slowly risen over time....it is 0ppm after the di

p.s. i have a 50 gpd rodi setup.....so 50 gpd membrane

[Buckeye Hydro]

Originally Posted by BuckeyeFS

Bennr - need a little more information to advise you well.

What is the TDS of your tap water?
What is the water pressure reaching the membrane?
What is the capacity (in gallons per day) of your membrane?
What is the TDS of your RO (not DI) water?

Russ

Sorry - that was for chilwil - the OP

[Buckeye Hydro]

Originally Posted by greg0385

Well i dont know bout his but mine is 40psi. Its 75gpd membrane. It makes 4cups of bad to a little over a cup of good. Feed water tds is 16-22 and after the membrane its 4-6tds. I only get 60-90 gallons of good water before my di is exhausted. I think mine is co2 and trying the bubble wand in a contsiner before the di chamber. Only problem is im out of di resin and have to wait.

Your RO water should be about 1 ppm. Something is wrong with your RO, or the way you are measuring the TDS of your RO.

Russ

[Buckeye Hydro]

Originally Posted by bennr

My tap water is 118ppm ..... not too sure what the water pressure into the membrane would be.....i just have it hooked up to the street water pressure and then it goes through the first 3 prefilters (5 micron, carbon, 1 micron) and then into the ro membrane and then into the post carbon.....it will store this water in the small tank and then push it rhru the di media whenever i turn the valve.....so i am not really too sure what the pressure is when it gets to the membrane....but i know that my water is currently testing 4ppm from just ro alone.....used to test 0 (rarely 1) but has slowly risen over time....it is 0ppm after the di

p.s. i have a 50 gpd rodi setup.....so 50 gpd membrane

Remember that RO membranes function based upon the difference in the pressure on the feedwater side of the membrane versus the pressure on the storage tank side of the membrane.
So for sake of discussion let’s say you have 50 psi tap water and your RO water goes to a 5 gallon bucket at 0 psi. So the membrane is operating at 50 – 0 = 50 psi net driving pressure.
Now, if you have your RO water delivered to a pressurized tank, when the tank is full it will provide pressure back against the membrane at 66 to 85% of the feedwater pressure, so 50 psi - ~38 psi = 12 lbs of net driving pressure. You can imagine what sort of rejection rate you’ll see at 12 psi.
So the TDS of RO water in a full tank will be substantially higher than the TDS in RO water delivered to an atmospheric (unpressurized) tank.

Bottomline - don't deliver water from a pressurized tank to a DI stage, and don't deliver DI water to a pressurized tank.

Russ

[chilwil84]

Originally Posted by BuckeyeFS

Bennr - need a little more information to advise you well.

What is the TDS of your tap water?
What is the water pressure reaching the membrane?
What is the capacity (in gallons per day) of your membrane?
What is the TDS of your RO (not DI) water?

Russ

-My tap water is in the 130s
-i have a booster pump pushing it to 65 before the first membrane(i have a dual kit but had the same issue at 50-55 before i put the dual kit on)
- dual 75
- RO is 4

i actually hooked up a t to bypass by DI for my FOWLR tanks because i am not real worried about a tds of 4 for them but my reef i would like 0.

[chilwil84]

Originally Posted by bennr

do you know what the ph is of your water straight from the well?? and after the neutrslizer?? i do not believe this would be the issue. my one buddy drills wells for a living and last night told me that carbon dioxide can be a problem in wells.....only way to know if you do have too much c02 is to test it he said but that would require the proper equipment. he slso said he would recommend you put water through the neutralizer and then into the rodi. try putting water through the neutralizer and then let it sit for a bit and stir it often....he said they do make equipment to remove c02 from well water...hope this will help. what are your tds readings before the neutralizer and then after the neutralizer?? i can see that it is 3 - 4 after ro before di.....which is what mine is right now...i am thinking of changing my ro membrane tho soon because when it is new i can get 0ppm out of ro alone before di.....the guy i bought my rodi off is a dealer and he said ro membrane should be changed when it reaches 4-5ppm....i might as well do my other filters too. I am two years on my membrane so i guess it might be time lol. How old is your membrane??

I am pretty sure my ph was 5.5 before and about 7 after (has been a couple 2 or 3 years since the test was done) i have a dual membrane setup. i just changed the 1st one about 2 months ago and the second is maybe a year old.

[Buckeye Hydro]

Originally Posted by chilwil84

-My tap water is in the 130s
-i have a booster pump pushing it to 65 before the first membrane(i have a dual kit but had the same issue at 50-55 before i put the dual kit on)
- dual 75
- RO is 4

You should be getting over 1000 gallons of DI water our of a standard 10" x 2.5" cartridge with your RO water - just considering the TDS. SO maybe somethng else is going on like CO2 as you mentioned. What is the alkalinity and pH of your RO water?

Russ

[chilwil84]

Originally Posted by BuckeyeFS

You should be getting over 1000 gallons of DI water our of a standard 10" x 2.5" cartridge with your RO water - just considering the TDS. SO maybe somethng else is going on like CO2 as you mentioned. What is the alkalinity and pH of your RO water?

Russ

i only get about 200 gallons

alk and ph before DI?

[Buckeye Hydro]

Originally Posted by chilwil84

i

alk and ph before DI?

Yes sir.

[chilwil84]

both gh and kh tests came back 20 or less

ph kit was exp over a year ago so i tossed it and its reading

[Buckeye Hydro]

If you can give me accurate readings on the pH and alkalinity of your RO water I can calculate the CO2 in the water.

Russ