CO2 Reactor observations

[spectre]

I've built a CO2 reactor based on Tom Barr's design. It is 18" tall by 2" wide (standard 2" pvc). I'm injecting pressurized CO2 into a piece of rigid airline pipe that is glued into the side of the reactor about 2 inches from the top and then bends and goes down inside the reactor about 8-9". I'm using a Fluval 304 canister filter to push water through the top and out of the bottom.

My setup is a 72 gal bowfront. From the bottom of the reactor to the top of the tank is approx. 4.5 ft.
When I set this system up to test run it I find that if the CO2 is off (It will be on a timer based on the light cycle) the water will creep into the rigid airline almost to the check valve I have after the bubble counter. This is a cheap plastic check valve right now. I have ordered some Clippard brass check valves to replace it before it goes on the tank.
My issue is when I turn the CO2 back on it does not push the water out of the rigid airline until I turn the regulator up to about 30 psi. From what I've read, most people run their low pressure side around 10-15 psi.

My question is will the higher quality check valve solve my creeping problem and does running the low pressure side at 30 psi pose any problems??

I apologize for this being so long, I just wanted to make sure I included all info.

Thanks for any help/advice you can give.

 

[VaughnH]

Water will creep back up a CO2 line because the water is dissolving the CO2 as it creeps. The check valve should stop water from going past it, but I find a little does get thru the check valve. I haven't had a problem pushing the water back when the CO2 comes on, but I run 3 or so bubbles per second, which makes it push the water back pretty rapidly. I have been running my regulator with an outlet pressure around 20-25 psi, so doubt that your 30 psi will be a problem. Right now with a much better regulator, installed a few days ago, I have the outlet pressure at about 10 psi, and still no problems.

My check valve is only about 6 inches from the reactor, so maybe that is why mine works well.

 

[ccLansman]

i have my co2 straight into the inline tube, no pipe down into the tube so my back pressure should be greater. I run my regulator at 10psi per the info on rex's site and it pushes the water back in a minute or less. 30psi seems way too high for such a low pressure situation, especially with another tube down into the reactor.

 

[spectre]

I'm thinking I must have a leak. I would think with having the CO2 inlet facing down with the current it would pull a slight venturi action and help pull the water back out after the CO2 comes back on. Apparently this is not the case. I can see the water in the CO2 inlet pipe pulsing to the amount of bubbles I inject, but it never "pushes" the water out. I must be loosing pressure between my bubble counter and inlet. I am using just standard Polyflow for the connections. I wouldn't think the extra pressure would be diffusing through the tubing wall that rapidly, so it must be one of the connections.
I have my check valve approx. 3" from the inlet to the reactor. When my new check valves get here I'll re-pipe the whole thing and check for leaks.

Thanks for the advice/help.

 

[spectre]

Well after playing around with the it I discovered the problem. My bubble counter is leaking around the seal. I took the bubble counter out of the loop and went straight to the reactor. Now I can push the water out with around 10 psi. I guess I'll be shopping for a new bubble counter..

 

[Gerryd]

Yeah, bubble counter leak! My old Milwaukee setup leaked all the time......

Glad you found your issue!