DI Resin getting used up fast ???

[SFish]

I have had my RO/DI unit for a bit less then a year now. I changed the prefilters on 6/23/14. I use to get 72 to 74 psi going into the RO but now it seem to drop to around 70. My Cl is at 0.58ppm. My rejection rate seems to be around 96 to 97 ish. I'm getting a TDS of around 8 to 11 ish coming out of the RO filter. I also have a flush kit on it that I use before and after. I changed the DI on 9/2/14. I packed it very tight when I did so. Tonight when I started making water the TDS out of my DI is reading 1 and it is all brown. I make about 15 gallons of water every two weeks. The DI resin only lasted for 3 runs of making water. My tap water TDS is around 288. What is causing the DI to go bad? Do I need new prefilters or an RO filter?

 

[SFish]

Here is from my log

6/9/14

PSI = 74
Cl = 0.19ppm
Rejection rate = 97%

6/23/14

Changed pre filters + DI

PSI = 72
Cl = 0.24ppm
Rejection rate = 97%

7/7/14

PSI = 72
Cl = 0.24ppm
Rejection rate = 96.68

7/22/14

PSI = 74
Cl = 0.29
Rejection rate = 95.85

8/18/14

Changed DI

PSI = 70
Cl = couldn't test because I ran out
Rejection rate = 97.3

8/31/14

Changed DI

Found out I wasn't packing DI tight enough

PSI = 70
Cl = 0.16 I'm thinking this test was messed up
Rejection rate = 96.3

9/10/14

PSI = 70
Cl = 0.29
Rejection rate = 97.4

9/28/14

PSI = 70
Cl = 0.58
Rejection rate = 96

10/9/14

DI is reading 2ppm

PSI = 70
Cl = didn't test because I stop filtering
Rejection rate = 97

I calibrate the TDS meters once a month. I've been cleaning the probes with 50% Isopropyl alcohol.

 

[E46Twist]

Are all of the pre filters relatively new?

 

[SFish]

I changed all of them on 6/23/14

 

[E46Twist]

And what are you taking your TDS readings out if? As in do you fill a little container to dip the probe in?

 

[disc1]

Are you on a well? Sometimes well water can be high in CO2 and that can pass the membrane and burn up DI resin really fast. If you are on a well, check the pH of the incoming water. If it is below about 6.5 or so you may need to set up a degassing setup after the RO and before you put it through DI.

If you're not on a well then ignore everything I just said.

 

[SFish]

And what are you taking your TDS readings out if? As in do you fill a little container to dip the probe in?

No they are in line meters

 

[SFish]

Are you on a well? Sometimes well water can be high in CO2 and that can pass the membrane and burn up DI resin really fast. If you are on a well, check the pH of the incoming water. If it is below about 6.5 or so you may need to set up a degassing setup after the RO and before you put it through DI.

If you're not on a well then ignore everything I just said.

I'm on city water no well and they use Cl gas.

 

[thegrun]

How much water are you making at a time?

 

[SFish]

About 15 gallons. I make water every two weeks.

 

[JammyBirch]

Had the same problem, it is high silica in my city water. Changed the di resin almost immediately. Sucks...

 

[SFish]

I can watch it start to change brown right away at the bottom and work it's way to the top over a few uses. They must have changed something then because when I first got the filter the DI lasted 6 months. Even at the 6 month mark the resin wasn't brown but my TDS started reading 1 so I changed it. Is there a prefilter to take that crap out? What would be considered high? The filter guys said it maybe CO2. In any case I think I may need another prefilter just don't know what.

 

[whosurcaddie]

I can watch it start to change brown right away. They must have changed something then because when I first got the filter the DI lasted 6 months. Is there a prefilter to take that crap out?

If you can watch the color change then its definitely some form of gas I used to be on well water and my di would do that. You need to degas the water and then send it through your DI by way of some type of small pump. Its a hassle and an extra step nobody looks forward to but if you want 0tds water its the only way.

The way you degas is you will need an airstone in the bottom of an extra water container and let it run for about an hour and then run the degassed water through your DI stage. This is after you send it through the ro unit of course. Good luck.

 

[SFish]

Thanks

 

[thegrun]

One thing you can do to at least get full use of your resin is to add a second DI canister. You will get a lot more use out of your DI resin if you run two canisters of resin in series. When you use a single canister of resin and you start to see your TDS readings rise you need to replace the resin even though it still capable of absorbing more pollutants. If you use two canisters when you first start to see your TDS rise, remove the first canister in line and then shift the number two canister into the number one position. Then replace the resin in the old number one canister and place it in the number two position. That way you get full use of the resin.

 

[asudavew]

Are you flushing your system during startup?

+1 on the dual di canisters.

 

[SFish]

Are you flushing your system during startup?

+1 on the dual di canisters.

Yes before and after

 

[SFish]

I found this

http://www.3reef.com/threads/now-you-can-accurately-test-for-co2.105983/

It a CO2 test for $16. Going to pick one up.

 

[SpectraPure]

If you are having a co2 problem I can help. I am very experienced in water purification and DI!

Jeremy
support@spectrapure.com

 

[SFish]

I have no idea if it's CO2 but something is eating my DI up. The CO2 kit is on it's way so I'll find out.

Thanks for answering my PM