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

[SpectraPure]

Please measure the ml/pm on the product and waste water lines for 1 minute each, and report what the TDS of the tap water, RO water, and DI water is. Also please tell me what the pressure reads on the pressure gauge.

Jeremy

[SFish]

I don't know what ml/pm is.

The pressure is 70PSI after the prefilters

TDS of tap water is 294ppm

TDS after RO is 10ppm

I changed the DI so the TDS is 0ppm

[SFish]

I posted my Log up above

[SFish]

Must have scared him off

[SpectraPure]

Chlorine gas gets removed by the carbon block. Co2 passes through the membrane only to be removed by the DI. Take a stop watch and a measuring cup to the product water for a minute, and then the waste water to report what your waste to product ratio is.

also. To get membrane rejection we take the tap water TDS minus the RO water TDS divided by the tap water TDS. Is this how you calculated your rejection?

Jeremy

[SFish]

Rejection rate I've been doing this

[(Tap TDS - RO TDS) / Tap TDS] x 100

So yes the same as what u did. I have to make water tonight so I'll get u the other numbers. It says that it should be 4.5:1 for my unit.

[SpectraPure]

Do you have a water quality report?

Jeremy

[SFish]

ok so 1min each

Waste water = 500mL

DI water = 250mL

What the hell??? It's coming out way to fast. I put the RO in like almost a year a go and have not touched it. The 1st thing of DI lasted months. The Di resin I packed the crap out of. How do I fix it???

[SFish]

Psi right now = 72psi

DI TDS = 0

Tap TDS = 246

RO TDS = 9

[SFish]

DI resin

[SFish]

Do you have a water quality report?

Jeremy

No

I called and checked a while back so I know they use Cl gas but that's all I know.

[SpectraPure]

Ok here is your problem. The RO production is normal. 250 ml pm is average for a 75 gpd at 50 psi, and a 90 gpd at 60 psi. On your system you have a flow restrictor. It is either an insert inside the waste line. It will have a capillary tail, or you have the barrel on the outside of the waste line and it has a ml marking on it say maybe 500ml. Now if you have the first flow restrictor you can cut some of the tail off to increase the waste water. This will allow your membrane to reject better, thus allowing your DI to live longer. If you have the second flow restrictor. Order the first, and in the meantime remove the barrel flow restrictor, and use a ball valve instead. Don't rely on the ball valve long term. Be sure to order a capillary flow restrictor. My part number is FR-90 if you have a 75 gpd or a 90 gpd. Other companies sell them as well.

By increasing your waste water, you will allow your membrane and DI to last much longer.

PS if you do not have a flush valve get one. My part number is VA-FVK-4. Other companies also sell them. If you buy one from another company make sure that it does not have a preset built in flow restrictor.

Please let me know if you need anything else answered. You couldn't scare me away if you tried!

=)

Jeremy
Support@spectrapure.com

[SpectraPure]

No

I called and checked a while back so I know they use Cl gas but that's all I know.

Call whomever you pay your water bill and ask for a total water quality report. They have to give it to you. It is important.

Jeremy

[SFish]

My filter is a 50gpd. The flow restrictor is on the outside I have not touched this at all and yes I have a flush kit.

[SFish]

flow restrictor

[SpectraPure]

The problem with the flow restrictor on the outside is that the screens clog up with calcium. this drops the waste ratio over time, and it causes premature DI exhaustion. Get a capillary flow restrictor rated for 800ml, or my part number is FR-60. Either way if you increase your waste water, your membrane will produce lower TDS, and then in turn will increase the life of your DI.

Jeremy

[SFish]

Thanks

I'll give it a go