RO/DI help

[lpsouth1978]

I recently setup a 40b, completed the cycle, and have 3 fish in it so far. My problem is with my water. I have a 6 stage RO/DI with Aquatec booster pump. I just replaced all of the filters and installed a new Filmtec membrane. My feed water is such poor quality I am only getting about 40 gallons out of my DI resin before it needs to be replaced.

My feed water TDS is at about 700. After the RO membrane it is only down to about 40. I cannot afford to replace the DI resin after each water change and ATO reservoir fill. Is there anything I can do, that won't cost me a small fortune, to improve my final product water and increase the life of my DI resin. It is about a 2 hour round trip to the nearest reputable source of quality, 0tds, water.

[shaginwagon13]

Originally Posted by lpsouth1978

I recently setup a 40b, completed the cycle, and have 3 fish in it so far. My problem is with my water. I have a 6 stage RO/DI with Aquatec booster pump. I just replaced all of the filters and installed a new Filmtec membrane. My feed water is such poor quality I am only getting about 40 gallons out of my DI resin before it needs to be replaced.

My feed water TDS is at about 700. After the RO membrane it is only down to about 40. I cannot afford to replace the DI resin after each water change and ATO reservoir fill. Is there anything I can do, that won't cost me a small fortune, to improve my final product water and increase the life of my DI resin. It is about a 2 hour round trip to the nearest reputable source of quality, 0tds, water.

Where did you buy your RO/DI unit from? Might be worth emailing them and seeing what they recommend.

I personally have never heard of an RO membrane or DI resin being used up after only 40-gallons tbh. You sure the membrane is working and or seated correctly?

[Vinny Kreyling]

Colorado is notorious for bad water.
If you get no satisfaction contact Spectrapure.

[mcgyvr]

I'd start by using a 99% rejection rate membrane..

[jrill]

Maybe add a second ro kit

[hkgar]

Are you on a well? You might want to consider a water softener.

[Tinkanator2000]

I'm going to say it could possibly be partially related to a CO2 issue. Do you know what your pH is prior to the unit? My well is very acidic and has high concentrations of CO2. This is apparently very common with well water. What I have to do is make just RO water and aerate it for 24 hours prior to pumping it through my DI resin. Doing this has increased the life of my DI resin enormously. My incoming TDS is only 200-300 and is 12-15 after the RO membrane though.

[hkgar]

Originally Posted by Tinkanator2000

I'm going to say it could possibly be partially related to a CO2 issue. Do you know what your pH is prior to the unit? My well is very acidic and has high concentrations of CO2. This is apparently very common with well water. What I have to do is make just RO water and aerate it for 24 hours prior to pumping it through my DI resin. Doing this has increased the life of my DI resin enormously. My incoming TDS is only 200-300 and is 12-15 after the RO membrane though.

Yup, I am on a well also. without aeration di one month, with aeration di 14 months.

[lpsouth1978]

I am actually now in Arizona and on municipal water. I never had issues in Colorado, my water was actually very good. I got the system about 2 years ago to use primarily for my drinking/cooking water, so 50-80 TDS was not a problem. When I set up my tank I added the DI.

I am considering running the clean water from the membrane through a 2nd membrane,but I am concerned that it would give me something like 1:8 waste water ratio.

[shaginwagon13]

Originally Posted by lpsouth1978

I am actually now in Arizona and on municipal water. I never had issues in Colorado, my water was actually very good. I got the system about 2 years ago to use primarily for my drinking/cooking water, so 50-80 TDS was not a problem. When I set up my tank I added the DI.

I am considering running the clean water from the membrane through a 2nd membrane,but I am concerned that it would give me something like 1:8 waste water ratio.

Arozona has feed water with TDS of 700?

Can you post a picture of what system your using? Also, what pre-filters and membrane are you using? Not all pre-filters and membranes are created equal.

[lpsouth1978]

Originally Posted by shaginwagon13

Arozona has feed water with TDS of 700?

Can you post a picture of what system your using? Also, what pre-filters and membrane are you using? Not all pre-filters and membranes are created equal.

I can try to get a pic tonight, but it is under the sink and not the easiest to get good pics of. I got the RO unit on amazon, same with the replacement filters and membrane. I am looking at ordering new filters and a new membrane from BRS as soon as payday arrives. I am also considering their "Triple DI saver kit". It sounds like that may be the way to go for me.

And, YES Arizona has TERRIBLE water. NO ONE drinks from the tap here. A whole house filter and water softener are pretty much standard. I however have neither and have to rely solely on my RO system.

[mcgyvr]

Cough... 99% RO membrane

[shaginwagon13]

Originally Posted by mcgyvr

Cough... 99% RO membrane

Lollll

Ya that is definitely a very valid point.


Sent from my iPhone using Tapatalk

[hkgar]

Originally Posted by mcgyvr

Cough... 99% RO membrane

And, in case you don't know how to google, here is a link.

[Poopapotamus]

Also on this site down low, Spectrapure has there own section of forum where they cover all kinds of useful information on making DI water. One thing I learned from them is... I had a float valve controlling the refill of my RODI water and it would start to refill as soon as my water level dropped enough to actuate the float valve. This is not the way it should be done. Now I have manual ball valves on my system,and once my second barrel gets down to about half full I turn the valves on and produce a huge volume of water all at once. This has greatly increased the quality of water I am making, and has increased the longevity of my DI resin. If you are making small batches of water... try to stop this practice! It sounds like you are making RO for the house with this system at well, but at least for your aquarium make sure you have at least one large barrel, and only make water for the aquarium in large batches. And obviously as numerous people have suggested get that 99% rejection filter, but note that if you are making small batches of water for the house... you will not get close to 99% rejection. I feel like your best bet would be to save up for a second system and have it run off your existing system.
Good Luck
Ron

[lpsouth1978]

I decided to make some upgrades to my RO/DI system. While I am keeping the system I have, I just ordered some 1 micron sediment filters, 1 micron Carbon Block filters, and a new 100 GPD membrane from BRS. The membrane is rated at 98% rejection, but that is the highest I could find for a 100gpd membrane. I also ordered the Dual DI Canister upgrade from BRS and extra resin.

I will also be redoing much of the tubing to setup the system more efficiently. I plan on using ball valves to keep the resin separate from the drinking water, so it is only used when making water for the tank. I am hoping that all of these changes will amount to better water and a healthy tank.

[wowzer]

I run BRS membranes with good results!

[Sisterlimonpot]

Where in Arizona are you?

[lpsouth1978]

Originally Posted by Sisterlimonpot

Where in Arizona are you?

I am southeast of Phoenix in Florence. We have Johnson Utilities and they are TERRIBLE.

[Sisterlimonpot]

ours is high but not that high. I'm in west valley, we get water from the white tanks and so far it's averaging 450-500

[lpsouth1978]

I replaced the sediment and carbon block filters and saw a very small improvement. I will have the new membrane on Wednesday and will see if that helps. I also tested my source water for ammonia and did not detect anything. How would I go about testing it for Co2?

[mcgyvr]

Originally Posted by lpsouth1978

I replaced the sediment and carbon block filters and saw a very small improvement. I will have the new membrane on Wednesday and will see if that helps. I also tested my source water for ammonia and did not detect anything. How would I go about testing it for Co2?

You shouldn't have seen any improvement for the most part..
Dissolved solids will not be removed by a sediment filter and a carbon block will also have little/no effect on them..
The membrane is doing all the work on the TDS levels..

Going with that fine of a micron will likely just cause them to get clogged faster thus lowering pressure post prefilters thus reducing efficiency of the membrane.. Probably wasn't the best move you could have made..
Thats still a 96-98% membrane too.. (96 min..98 typical)..
You are maybe getting around that now..

So don't expect much..
I should have asked if you had 75GPD or 100GPD or what..

[lpsouth1978]

Originally Posted by mcgyvr

You shouldn't have seen any improvement for the most part..
Dissolved solids will not be removed by a sediment filter and a carbon block will also have little/no effect on them..
The membrane is doing all the work on the TDS levels..

Going with that fine of a micron will likely just cause them to get clogged faster thus lowering pressure post prefilters thus reducing efficiency of the membrane.. Probably wasn't the best move you could have made..
Thats still a 96-98% membrane too.. (96 min..98 typical)..
You are maybe getting around that now..

So don't expect much..
I should have asked if you had 75GPD or 100GPD or what..

Yeah, I didn't see much change at all, just a couple of points and that could be from changes in the source water. 700 TDS is on the high side, it normally ranges around 530-620, but can vary from time to time. I figured I am getting roughly 93% rejection rate from my current membrane. Last night my source water was at 598 TDS and after RO was 39 which equates to roughly that 93%. I am using a 100gpd system and the new membrane should do better with specs stating 96-98% rejection. This should put my post RO between 12-24 TDS. Not perfect, but better than 40.

[lpsouth1978]

I got the new membrane today and installed. NO improvement. I am still getting just under 93% rejection. The system has a 600 mlm flow restrictor, but most of the things I am reading say that 800 is ideal for a 100gpd system. Would replacing the flow restrictor improve my rejection rate?

[mcgyvr]

Originally Posted by lpsouth1978

I got the new membrane today and installed. NO improvement. I am still getting just under 93% rejection. The system has a 600 mlm flow restrictor, but most of the things I am reading say that 800 is ideal for a 100gpd system. Would replacing the flow restrictor improve my rejection rate?

Call Russ at Buckeye Hydro..
He will get you hooked up/down the right path..

A proper flow restrictor is important and will effect membrane performance..