interesting RODI finding

[polywise]

So, I have been reefing since 1988.

Got myself a RODI unit in 2003 wanting to improve the water quality that I was using for my tank.
I have a well, and the water seems to plow through DI resin rather quickly. I just accepted that fact.
fast forward 20 years, a lot has changed & there is a TON of info and experience feedback out there.

What I wanted to try.. was to change up my RODI system to remove as much CO2 that is in well water.
Some people were saying to do a large open container of well water prior to RODI unit with an airstone to blow off the CO2
before running through the RODI unit ( which is a good way to do it ).

This is what I did differently
I took the DI unit off of the main system. Still run 1&.5 micron sediment filters to the RO membrane, then into a carbon filter where the DI resin used to be. That water goes to a large open container where I have an airstone to blow off the CO2.
The RO unit produces a good amount of water way more that evaporation needs so I let the container fill and then turn off
the RO unit for week until the container gets near empty.

Here is my interesting finding .... I use an apex DOS to control for evaporation, slowly the aerated water is pumped through a DI canister This slower flow rate gives more contact time in the DI canister, and the slower flow rate does not out strip the DI resin's ability. It noticeably lasts much longer before needing to be changed.

Share your experience if you have tired something like this.

Thanks,
Jim C,

 

[SantaMonica]

Yes I think that for most flow-through absorption filters of any kind, the slower the flow the better the absorption.

 

[mellotang]

maybe the DI resin is lasting longer because you’re degassing the CO2 with the air stone?

Maybe it doesn’t have anything to do with the slower flow?

 

[Josh]

Absolutely, the higher pressure will force the sediment through the media.

 

[polywise]

I think its a combo of both. Degassing of the CO2 helps a bunch, but more so the
(slow flow for tank evaporation make up) through the DI resin.
Either way I am happy with the results.

 

[rohitkhatri]

Yes I use DOS too

 

[devi23devi gh0st]

So, I have been reefing since 1988.

Got myself a RODI unit in 2003 wanting to improve the water quality that I was using for my tank.
I have a well, and the water seems to plow through DI resin rather quickly. I just accepted that fact.
fast forward 20 years, a lot has changed & there is a TON of info and experience feedback out there.

What I wanted to try.. was to change up my RODI system to remove as much CO2 that is in well water.
Some people were saying to do a large open container of well water prior to RODI unit with an airstone to blow off the CO2
before running through the RODI unit ( which is a good way to do it ).

This is what I did differently
I took the DI unit off of the main system. Still run 1&.5 micron sediment filters to the RO membrane, then into a carbon filter where the DI resin used to be. That water goes to a large open container where I have an airstone to blow off the CO2.
The RO unit produces a good amount of water way more that evaporation needs so I let the container fill and then turn off
the RO unit for week until the container gets near empty.

Here is my interesting finding .... I use an apex DOS to control for evaporation, slowly the aerated water is pumped through a DI canister This slower flow rate gives more contact time in the DI canister, and the slower flow rate does not out strip the DI resin's ability. It noticeably lasts much longer before needing to be changed.
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Share your experience if you have tired something like this.

Thanks,
Jim C,

That actually makes a lot of sense, especially with well water that’s heavy in dissolved CO2. Slowing the flow through the DI after aeration is a clever workaround — sounds like you’re giving the resin a much better chance to do its job instead of exhausting it all at once.

Pretty cool seeing how a small process change can stretch DI life that much. Have you measured how much longer the resin lasts now compared to your old setup?

 

[polywise]

Did not keep track of timing.. I would change the DI resin when TDS meter started to move. Now all I can tell you is that It is noticeably longer timeframe.
Sometime I feel like is the TDS meter working? but at some point it moves.
On my next couple of DI changes .. I'm going to keep notes on how much water the tank goes through.

I'll come back in the fall with some feedback