DI resin question

salty joe · Aug 30, 2020

I changed my DI resin today but am getting a TDS reading of 1. The water coming out of my RO filter reads 2, so that part is good.

My question is, if DI resin dries out, is it damaged? My new DI resin was mostly dry....

I always got a reading of 0 with my RO/DI setup.

FreakPrism · Aug 30, 2020

Have you let it run for 15 or so minutes, discarded the water, and then checked the reading?

Which DI resin are you using?

salty joe · Aug 30, 2020

It's been running for a couple hours and I still have a TDS reading of 1. I need the water so I'm going to use it, I don't think a TDS of 1 will hurt.

The resin is a no name off ebay. I've been using no name mixed resin of ebay for years with good success but this was dry. I wonder if DI resin getting dry hurts its performance.

RobB'z Reef · Aug 30, 2020

Brs always says that once opened it can go bad after a while. Perhaps that's what they meant? That or they like to sell DI lol. Either way, maybe there is something to it.

piranhaman00 · Aug 30, 2020

Did you pack it down properly? See any channeling?

salty joe · Aug 31, 2020

After I filled the canister and put the lid on, I bumped the bottom of the canister to compress the resin then added another inch or so. Is that the right way to pack it?

Anyway, this morning I get a read of 0 TDS. I still have 2 TDS coming out of the RO.

piranhaman00 · Aug 31, 2020

salty joe said:
After I filled the canister and put the lid on, I bumped the bottom of the canister to compress the resin then added another inch or so. Is that the right way to pack it?

Anyway, this morning I get a read of 0 TDS. I still have 2 TDS coming out of the RO.

That should work alright but could cause issues. I use 1.5” pvc with cap end and pack it like a muzzle loader

airmotive · Aug 31, 2020

The last time this happened to me, I had put the DI cartridge back into the canister upside down. Worth a check.

Opus · Aug 31, 2020

airmotive said:
The last time this happened to me, I had put the DI cartridge back into the canister upside down. Worth a check.

I've done this also. There should be an arrow on the catridge showing which way to install it.

Dried out DI is supposed to decrease its efficiency but I used di that had been dry for over a year and I didn't notice any difference. It still should give you 0 tds just get used up much quicker.

PatW · Aug 31, 2020

My tds reading after the RO membrane is also 2 tds. When I start getting a reading of 1 post DI, it is an indication that the DI resin is pretty much used up or I did not pack it tight enough. I use color changing resin but really don’t have to. It is nice to know about when it is nearly depleted. By the way, I don’t think you can pack resin too tightly. I use the tap method but I do it a bunch and fill the canister just as far as I can.

Uncle99 · Aug 31, 2020

Those TDS checkers are not absolutely dead on, I never change until we get more than 5ppm.

salty joe · Aug 31, 2020

Interesting conversation-thanks all. Now, I'm getting a read of 2, so the DI resin seems to be doing nothing. I will make sure the cartridges are installed correctly and also I'll pack the resin tighter. I appreciate the suggestions.