Mystery Solved! YahoO
For the last few times now my BRS color-changing DI resin has been disappearing after a few days. It depletes 5-10% then :-)### Gone. So I changed the RO membrane and that didn’t help. Problem was the old compression sponge at the top. After years of use to was down to nothing. I had been stretching it out each time before, but it was still only 3/8". Luckily I had a spare. The new sponge is over 1" thick. Problem Solved!
What did the sponge have to do with it? Was it full of gunk?
The sponge keeps the small pellets in. From what it sounds, it was so worn it was not doing its job.
Did you mean the pellets were physically disappearing? DI resin doesn’t dissolve, it gets used up.
[quote=“Floating13, post:3, topic:8494”]
The sponge keeps the small pellets in. From what it sounds, it was so worn it was not doing its job.[/quote]
Correct
[quote=“icecool2, post:4, topic:8494”]
Did you mean the pellets were physically disappearing? DI resin doesn’t dissolve, it gets used up.[/quote]
Yes, the pellets themselves were breaking down. After the +/- beads loosened, they neutralized each other depleting the media and removing all deionizing properties. Since there was extra space in the canister, the neutralized media tumbled in the canister and broke down which only exacerbated the problem. This left a yellow white residue in the water change bucket.
Even with poorly packed DI resin though the worst you would get is channeling and you’d deplete localized areas (aka it would change color). Your volume shouldn’t change. I don’t know the particular canister you’re using, but DI resin doesn’t dissolve and you shouldn’t have enough flow for it to tumble. DI needs “long” contact time.
The residue in the water change bucket is probably from your salt. Do you test the TDS of the water coming out of your DI?
If it’s not breaking down, where did it go? I started with a full packed canister (packed down HARD) and a week later all the beads have separated and I’m left with less than half of the original media. Where did it go? I can see it slowly tumble in the BRS canister. I also stopped seeing the residue in the bucket once I fixed the problem.
I tested TDS out of the RO membrance and it’s in the single digits. Past the DI canister with tumbling media its 150 ppm.
what kind of DI canister do you have? the 1/4 inch line coming from your RO into your DI should not have enough flow to tumble a packed DI canister.
Even a 120 GPD unit in summer is only putting out 5 GPH flow, you should not even need a sponge, a screen should be enough to keep the resin contained.
[quote=“bnelson, post:8, topic:8494”]
If it’s not breaking down, where did it go? I started with a full packed canister (packed down HARD) and a week later all the beads have separated and I’m left with less than half of the original media. Where did it go? I can see it slowly tumble in the BRS canister. I also stopped seeing the residue in the bucket once I fixed the problem.
I tested TDS out of the RO membrance and it’s in the single digits. Past the DI canister with tumbling media its 150 ppm.[/quote]
It is breaking down from tumbling, it doesn’t break down during normal use. My setup has a simple cloth filter to catch large particles, but nothing compressible on the top. You want it to stay packed the whole time.
What’s the source of flow into that chamber? I’m concerned you are able to tumble the media at all.
Agreed, it’s breaking down from tumbling.
The flow is coming from the RO membrane so its very low. Since the beads are so small, it doesn’t take a lot of flow to churn them.
[quote=“Hudzon, post:9, topic:8494”]
what kind of DI canister do you have? the 1/4 inch line coming from your RO into your DI should not have enough flow to tumble a packed DI canister.
Even a 120 GPD unit in summer is only putting out 5 GPH flow, you should not even need a sponge, a screen should be enough to keep the resin contained.[/quote]
Agreed, but this canister compresses the media using a sponge. The old one was worn out so it wasn’t under compression. After a few days the media settled out and separated.
Here is my question, if the resin was “packed in” that sponge doesnt take up that much space once installed. How are you getting enough space for it to tumble? Unless your leaving too much space for the sponge to fill. I have some sponges that barely fill the space and have never seemed to have that kind of issue b4. Not saying its not poss,just never had an issue.
Ok so now the next question is, if the resin is in fact tumbling and disolving, that is now going into the tank? What kind of concern does this pose?