DIY CO2 Degassing Chamber for RO/DI

[TheEngineer]

Hmm. Even if you have half the housing filled with air, it doesn't affect the flow of water through a standard axial-flow, vertical DI cartridge.

Russ

Best I can guess is that it has to do with the volume of water pulling down from the degasser. I’ve equated it to a larger siphon tube in my head.

 

[BigJohnny]

Yeah I'm not sure what the issue is, I guess just flow differential. It's leaving the di canister at a pretty good rate, seems faster then before, but still comes spilling out the top of the degasser, I'm going to attempt to cut it apart tonight and make and length adjustments, also considering maybe adding a diaphragm pump between the degasser and di canister

You could have your DI resin packed too tightly. I have a co2 degasser (although mine is taller and wider) and if I pack my resin too tightly I can see the water level in the outside part of the DI canister gradually rising, so I remove just a little and then it flows great. Here is mine for reference:

 

[ctyler85]

You could have your DI resin packed too tightly. I have a co2 degasser (although mine is taller and wider) and if I pack my resin too tightly I can see the water level in the outside part of the DI canister gradually rising, so I remove just a little and then it flows great. Here is mine for reference:

I'm starting to think that might be the issue. I've shortend the return side of the degasser and extended the gas side of it and even changed the hose size from 1/4 to 3/8 and it will flow great for about 5 gallons and then back up and blow out the top of the degasser. I ordered a diaphragm pump to move the water from the degasser to through the DI chamber /shrug

 

[Buckeye Hydro Verified Sponsor]

Guys - you WANT the resin packed very tightly.

Russ

 

[ctyler85]

Guys - you WANT the resin packed very tightly.

Russ

This is what I thought, I had always heard you want it as tight as possible so there is no flex in the canister

 

[Buckeye Hydro Verified Sponsor]

In an UPflow mixed bed DI cartridge, if the resin is not packed tightly, the bed will fluidize and the anion and cation beads will separate. Best treatment occurs when the beads are thoroughly mixed.

Russ

 

[BigJohnny]

There is a difference between packing tightly and overpacking DI resin. I can pack DI resin until its clogged (even without a degasser)

 

[BigJohnny]

There is a difference between packing tightly and overpacking DI resin. I can pack DI resin until its clogged (even without a degasser)

I think i should have said "overfilled" instead of packed too tightly, although they are not mutually exclusive . You are correct in that you wanted it packed tightly, but not overfilled to the point the sponge compresses and obstructs flow.

 

[Buckeye Hydro Verified Sponsor]

you can remove the sponge - not needed

 

[Buckeye Hydro Verified Sponsor]

I can pack DI resin until its clogged (even without a degasser)

Hmm. We have been packing DI carts as tight as humanly possible , and compressing the sponge, for 20+ years, without ever limiting flow. The flow through a DI cart is only at the speed an RO can produce - very slow.

 

[BigJohnny]

Hmm. We have been packing DI carts as tight as humanly possible , and compressing the sponge, for 20+ years, without ever limiting flow. The flow through a DI cart is only at the speed an RO can produce - very slow.

Guess I'm super human strong then, I am "Big" after all ; ). All I know is that if I over pack my DI the flow is restricted too much for my degasser to work properly without overflowing. I will say that this has only happened once or twice. I still pack it very tight and compress the sponge, but I don't overfill it to the point that the 1/2" sponge is as thin as a paper clip. Maybe the sponge is the issue, OP could try removing that first.

My degasser works great, and I get at least 4x the efficiency now. Just trying to help the OP. Even if it does lose some efficiency (dont believe mine does because it's not fluidized and I believe packed very tight), as long as the OP is getting 0 tds water and his degasser is actually operational (not overflowing), he's reducing his resin consumption and is better off than he was before.

 

[Buckeye Hydro Verified Sponsor]

Ah-ha. Up-flow DI carts are packed assuming the flow is pressurized (think RO water coming from a membrane).

Russ

 

[ctyler85]

Ah-ha. Up-flow DI carts are packed assuming the flow is pressurized (think RO water coming from a membrane).

Russ

Where as now it's essentially gravity feed from the degasser. Hopefully this diaphragm pump does the trick and isn't Overkill

 

[BigJohnny]

Ah-ha. Up-flow DI carts are packed assuming the flow is pressurized (think RO water coming from a membrane).

Russ

Not sure what your saying here, just a tidbit of info?

 

[Buckeye Hydro Verified Sponsor]

So if you have some pressure feeding the DI, you won't ever have trouble with resin being "packed too tightly." But you're trying to feed it with gravity flow at almost 0 psi.

 

[ctyler85]

So if you have some pressure feeding the DI, you won't ever have trouble with resin being "packed too tightly." But you're trying to feed it with gravity flow at almost 0 psi.

My fear was that maybe it would be too much pressure/flow for the resin or maybe I'd end up pumping air into it somehow

 

[ctyler85]

Didn't mean to hijack this thread at all. Well I can say the degasser has worked miracles at saving my DI resin, but on the other hand its just become a giant PITA and I can not get this thing to stop flooding the house. installed a diaphragm pump, smallest I could find, 1.1gpm and 35psi, its too much flow and too fast and drains the degasser, runs dry and just pumps air through the DI resin. the only option I have right now is I put the diaphragm pump on a wave maker to give it a break between running so its not pumping air. I cant seem to come up with a happy way to run this system without causing a flood.

 

[TheEngineer]

To make my life a bit simpler, I've just been using a 5g bucket. I fill it with RO and let it aerate for 24 hours. There is a tap on the bottom that I open and it is gravity fed through the DI into a second bucket. Works fine, but isn't on demand like the original design here. You could use a float valve at the top of the tower to shut it off if it gets too high.

 

[ctyler85]

To make my life a bit simpler, I've just been using a 5g bucket. I fill it with RO and let it aerate for 24 hours. There is a tap on the bottom that I open and it is gravity fed through the DI into a second bucket. Works fine, but isn't on demand like the original design here. You could use a float valve at the top of the tower to shut it off if it gets too high.

I'm running out of real estate in the closet, I thought about doing this because Ive seen a bunch of designs with people aerating in buckets and pumping from the bucket into the DI. Next option would be to move the entire set up into the garage which is on the other side of the house so getting water where I need it will be a PITA, plus I'm usually making 40 gallons at a time

 

[Maine Reefer]

Well, I learned the hard way that the water coming out of my well has a high CO2 content. I burned through a pound of DI resin and only got 40 gallons out of it.... To keep this from happening again, I could either buy lots of RO/DI water or remove the CO2 from the RO water before I pass it through the DI resin. (This design is based off of the Spectrapure design.)

Parts List:
3" PVC (36")
3" PVC Cap
3" Knock-out Cap
3" to 1.5" PVC Tee
1.5" PVC Street 90 Elbow
1.5" to 3/4" Reducing Bushing
3/4" PVC (12")
3/4" PVC Threaded Coupling (Female)
3/4" Male Thread to 1/4" Quick Connect Adaptor
Air Pump
Air Stone
PVC primer and cement
Teflon tape



Assembly:
The parts are shown in the image above in the order you would connect them.

1. Cut the 3" PVC pipe about 6" down
2. Attach the 3" PVC cap to the bottom of the longer section from step 1
3. Attach the tee between the two pieces.
   
4. Attach the street elbow to the tee and the reducing bushing to the street elbow
5. Attach the piece of 3/4" PVC pipe to the reducing bushing (you can shorten the pipe if you'd prefer)
6. Attach the threaded coupling to the 3/4" PVC pipe
7. Apply teflon tape to the thread-to-quick connect adaptor and thread it onto the coupling from step 6
8. Drill 3 3/8" holes into the knock out cap
9. Thread the airline tubing through the bottom of the knock out cap, be sure the air stones are on the bottom!
10. Insert the knockout cap into the top of the short section of 3" PVC
11. Attach the air line(s) to your air pump
12. (OPTIONAL) Secure your air pump to the 3" PVC
13. Insert the output of your RO filter into the remaining hole of the knock out cap (only insert it a few inches)
14. Attach your DI chamber to the 1/4" quick connect fitting
15. That's it!

Use:
To use the degassing chamber, simply run your RO water into the chamber with the air pump running. As the water enters the chamber, it will be oxygenated and the CO2 level will be reduced. When the water level is high enough, it will trickle out of the tee and through your DI resin. Put the output of your DI resin into a bucket or holding tank and it is ready for use.

I have the same problem. I'm filling up my 65 gallon aquarium, and I've only filled it up about 40% of the way and my DI resin is almost all changed. About how much did this cost? And do I need two DI chambers or will one work?