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DI resin "shrinking" over time?

Meshmez

Supporting Member
Has anyone ever noticed that as DI resin gets depleted it seems to shrink?
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My other 2 canisters which are not depleted are still packed nice and full, and this one was fine until it the bottom 1/8 was completely white in color. I certainly didn't pack it this loose. Has anyone noticed this before? And is it still OK to use?
 
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What's the tds meter say right after this stage? It might deplete your mixed resin faster but I think it's fine. Is that your anion?
 
What's the tds meter say right after this stage? It might deplete your mixed resin faster but I think it's fine. Is that your anion?
Yes anion. I'm not running it right now so not sure about the tds. I assume the upper half is till working. It's just weird.
 
Yes anion. I'm not running it right now so not sure about the tds. I assume the upper half is till working. It's just weird.
Last time I replaced my resin was the first time I replaced it. Does it usually smell horrible or did I just get a weird batch?
 
I haven’t noticed the smell part, I wonder if it depends on brand? I’ve used Spectrapure pre-packed and bulk BRS mixed beds for both DI canisters.

The DI beads should not lose volume as they deplete. Probably just settling in more over time is my guess. That’s why packing gets extra attention up front plus use of compressed sponges.
 
I haven’t noticed the smell part, I wonder if it depends on brand? I’ve used Spectrapure pre-packed and bulk BRS mixed beds for both DI canisters.

The DI beads should not lose volume as they deplete. Probably just settling in more over time is my guess. That’s why packing gets extra attention up front plus use of compressed sponges.
I have noticed the smell more on the separate resins than the mixed bed.

I don't think it's from settling. The other 2 canisters were packed the same way at the same time. I have only ever seen it happen on partially depleted canisters.so while it's always possible, I don't think that's the main cause. Also that's a LOT of settling.
 
DI resin chemistry involves 1:1 ion exchange of desired ions for undesired ones. So it isn’t supposed to physically shrink as far as I know. Also the dead fish smell is probably mostly amines, which should have been removed by the carbon if they were coming from the water, so more likely are coming from one of your components. Maybe it is partially decomposing? Have you asked the vendor yet? Maybe they have a good explanation.
 
I never really looked before. But my Anion does seem a bit lower. It is about half depleted. Cation is fine.
The thing is, I really don't know if it was really full to begin with.

@JVU : Different Ions can be different sizes. Although I tend to think that would be pretty minor.
 
DI resin chemistry involves 1:1 ion exchange of desired ions for undesired ones. So it isn’t supposed to physically shrink as far as I know. Also the dead fish smell is probably mostly amines, which should have been removed by the carbon if they were coming from the water, so more likely are coming from one of your components. Maybe it is partially decomposing? Have you asked the vendor yet? Maybe they have a good explanation.

The smell come from the new resin the second you open the bag. It's from brs.
 
@JVU : Different Ions can be different sizes. Although I tend to think that would be pretty minor.
Yeah I thought about mentioning that but have to carefully calibrate my nerdiness to reduce eye-rolls. IF we want to go there though, the ions being released are small/simple and those being bound are generally much larger and more complex, so if this made a difference (I don’t think it does) the DI beads would increase in size as they get used up.
 
Yeah I thought about mentioning that but have to carefully calibrate my nerdiness to reduce eye-rolls. IF we want to go there though, the ions being released are small/simple and those being bound are generally much larger and more complex, so if this made a difference (I don’t think it does) the DI beads would increase in size as they get used up.
OK guys...really? Isn't most of the volume of the beads the actual resin?
 
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