[pairustwo]

So my DIY CO2 system was driving me nuts.
I had two 2 liter bottles, a bubble counter, and a tube running down to the intake of my fluval 204 (air stone and intake were stuffed inside a filter sponge).

It wasn't working. I could see the gas travel 1/2 way down the tube but stop.
I realized that putting the air stone closer to the surface let the gas bubble into the tank. Apparently the depths of my 20 gallon tank created to much pressure.

But now I had a diffusion problem. I couldn't get the bubbles into the canister.
So I attached a nylon filter bag to the output of the fluval, put tube with the air stone in the bag and weighted it down with some rocks. The rocks keep the bag from rising to the surface and letting the gas out.

The bubbles collect in the bag while water is forced through the bag. The only bubbles that escape are TINY. Some bubbles are clinging to the inside and the large bubble that collects at the top of the bag never gets enormous.

I think it is working. My drop checker is lightening up as we speak.
I looks like hell but it will do until I can think of something else.

 

[essabee]

I can give you another ugly reactor idea which works. Cut the bottom out of a 2L soda bottle, fit it to a power-head the bottom of the bottle pointing downwards, connect your DIY CO2 line to the venturi, switch on.

At least you can hide this ugliness in a rear corner.

 

[pairustwo]

I don't think I can hide anything in my 20 gallon tank.
I want to avoid a powerhead because of
Price
Another piece of equipment hanging in the small tank
No more power outlets.

 

[Galactic Doug]

I just bought a "Nutrafin" brand bubble counter and it works pretty darned good. The bubbles become so small by the time they reach the top they are almost non existant. It also has the ability to be hidden behind any wood ar plants because it is slim at only about 3/4" by 7" tall.

http://pet-king.stores.yahoo.net/15561176989.html

Good luck.

Doug