An idea for minimizing sump degassing AND mixing CO2 (pic, please critique)

G

gummyworms

AC Members
Jan 24, 2008
12
0
0
39
Hello,

Been thinking about how to most efficiently mix CO2 and prevent sump degassing and I came up with this.

The idea is to combine a DIY CO2 reactor with a Sump gas trapper. See pic:

Idea.gif


Problems I see with this:

1. With so much air coming in from the top, would it just displace all of the water in the tube?
2. Since the return is half air / half water, would excess air / co2 just escape up the return instead of diffusing into the water?

Let me know what you think!
Shawn
 
That's actually not a bad idea. The problem is that there is always some volume of air coming down the drain with the water (unless you're siphoning, which you shouldn't be with an overflow), so that air will continue to build up in that little chamber until it starts bubbling out the bottom, negating the effect of the gas trap. My thought was always just to seal the sump up as much as possible to catch any gas from escaping.
 
Sploke, I syphon with 4x 3/4" hoses from the main tank into a 'overflow' tank.
The main tank has a tank-deep overflow box and this setup allows me to have absolutely no air coming down the returnline because my return is deep under water in the external overflow with the sump-return.
Actual level in the Display tank only falls by 1 inch after power-cut.

The main issue I found with overflow boxes and syphon tubes is that the external box is to small and shallow in dept to hold enough water to 'drown' the overflow in water.

- Say you have 10" dept in your overflow box with the return to the sump.
- Then syphon tubes should reach 9" deep into it
- The opening of the return-tube to your sump is at 8" dept to keep syphon during power-failure
- The level of your Display Tank level is at 1" from the top (and therefore the level in the overflow box is as well)
- So there would then be 7" of water on top of the return-line opening in the box

In the display tank, your overflow box should be of equal or more dept of course.
If you can't get the level in the overflow box equal to the level in the display tank then add more or larger syphon-tubes because that's the bottle-neck then.
 
I've been looking at this a lot lately, not so much for sumps but CO2 diffusion in general. From the research that I've done, and what I've seen Tom personally recommend is sealing the sump with a lid and duct tape. As far as diffusion, I would look into something like this. Again, from my research this is the most efficient system I could find. Rex Rigg also has a set up, but I like Tom's better. If you used something like this leading into a sealed sump, you should be golden. :thumbsup:

IMO, if you don't seal the sump you're going to lose a lot of the CO2 that manages to get into the water to off-gassing.
 
Gummyworms, hope it doesn't look like I'm hijacking your thread.
Your suggestion should be quite interesting to try and in my case, with no air coming into the mix, might actually work.

Only problem I'd see is that CO2 can go up the water-line. So you'd have to add a gas-trap in your waterline to avoid this.
With that Gas-Trap, you could also put in a venturi-loop to circulate the CO2.
 
I'd just stick with a non vented wet/dry tower, this solves the issue, adds some bio, adds O2, keeps the CO2, and works better that the idea you had above.

Why?

I've tried it a few times, same type of thing.

Gas builds up and burps out, well, I suppose if the pipe is really large enough, I used a 4" pipe for 450 gal/hr, it was a PITA and the water level really affected things and bubbles still escaped.

In the end, I simply bought a decent wet/dry tower, sealed and that's fine.
No issues.

You can try the other way, but do not expect it to work quite the way you'd hoped. You might be okay with it even....but comparing it to the sealed chamber, there's simply none to made.

I've been far happier and had much less issue using a regular sealed wet/dry filter + a stockman/hofner gurgle buster etc overflow with a drop of about 2-3" over the spill way.

Regards,
Tom Barr
 
Tom,

Do you think you can say a little more about what you mean by the wet / dry tower? Does the return from the tank flow into this tower sitting in the sump?
 
Thanks for the pics.

So the top of that tower is sealed... Do you know where the extra air coming down get out? Or does it just diffuse into the water?
 
You must log in or register to reply here.
AquariaCentral.com
Top Bottom