Ro/di Puzzler

Salty Cracker

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Rocky Mountains BC
So I have 2 RO/DI setups here, one with 3 pre-filters, and one with 2, and 4 DI stages. Yes 4.


New membrane in one, the other membrane is likely fairly new. TDS in is ~130, out is 11. They're both 100GPD membranes and restrictors.

I have tried 1 to 4 DI sections, all with brand new DI media. Water coming out of the DI? 11! I have the lines hooked up through the proper connections I think (one is marked "INPUT", and I can't read the input on the 2-canister one, but I assume they all run right in to left out...regardless, I know that the 2 separate DI cans are running the correct direction, but why on earth am I not getting the TDS down to less than what's going in? Pressure is a steady 60PSI. I think 12TDS out of the RO section is fairly standard, that's what my upstairs drinking faucet outputs too. But does anyone have any idea why, or have come across this? The media inserts had arrows on them, so they should be the right orientation, but at this point I'm questioning everything about the DI setup. I mean, there's FOUR of them and they're not taking out 1 PPM of dissolved solids. On my old setup I ran just one canister, and it would last for months before it would edge up to 1, so no idea what's going on. Figured I would see if anyone has an idea. ???
 
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Kyle1970

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Nov 16, 2014
Location
Ayr, Ontario
RO output sounds good.
I would take all DI offline and try one at a time?
Could be a bad batch of resin?
Or a bad TDS meter perhaps.
Anyone local to you that can test the water?
 

Salty Cracker

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Rocky Mountains BC
RO output sounds good.
I would take all DI offline and try one at a time?
Could be a bad batch of resin?
Or a bad TDS meter perhaps.
Anyone local to you that can test the water?

The DI resin is from 3 separate suppliers
I have 2 TDS meters (bought a second one for reason you stated)

I did start with 1 canister, I figured with a whole new RO setup that I should be able to get away with only 1, but it made no difference, and I added them on, with no change in results.

I've even reduced the pressure, sort of to slow it down, in case the 100GPD was too fast for the resin do do it's job, and still no change. I could see one canister being faulty, but not all 4, and one of them ran on my old RO/DI and kept TDS to zero. I just can't seem to figure this out. I've even drained the cans, just to see if they re-fill themselves (or were just bypassing them all completely, and yes, they do slowly fill.
 

Salty Cracker

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Rocky Mountains BC
Okay, well chalk this one up to "Salty Cracker is a Dumbass".

So the new RO unit I picked up had different DI caninsters in it than the ones I had, these had arrows, and I 'assumed' that the arrow meant "insert this way", but evidently it meant "this way up".

So I had installed them the way my old ones were in (which I was having trouble with), and even with one canister TDS is down to 0 again. So instead of deleting this thread, I'm going to leave it up, on the off chance someone is as stupid as I am (yeah I know not likely), and has a similar problem. So the ARROW MEANS UP!!!

So this is the proper orientation of the canister. The two older ones I have don't have a mark on them, and they FIT IN BOTH WAYS!!! Ah well, at least I have it figured out, so now I can have a scotch and celebrate my incredible cleverness.
4.jpg
 

Copperkills

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Nov 8, 2015
Location
London
Okay, well chalk this one up to "Salty Cracker is a Dumbass".

So the new RO unit I picked up had different DI caninsters in it than the ones I had, these had arrows, and I 'assumed' that the arrow meant "insert this way", but evidently it meant "this way up".

So I had installed them the way my old ones were in (which I was having trouble with), and even with one canister TDS is down to 0 again. So instead of deleting this thread, I'm going to leave it up, on the off chance someone is as stupid as I am (yeah I know not likely), and has a similar problem. So the ARROW MEANS UP!!!

So this is the proper orientation of the canister. The two older ones I have don't have a mark on them, and they FIT IN BOTH WAYS!!! Ah well, at least I have it figured out, so now I can have a scotch and celebrate my incredible cleverness.
View attachment 19793
TDS=The Dumbass Saltycracker
 
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