OK folks, I did this as cheaply as possible. I had built one based on the image at the beginning of this thread. However, it didnt do to good of a job with more than two 2-liter bottles. I added a third and it couldnt keep up. The jar was too small and there wasnt enough agitation to break the Co2
up into smaller bubbles.
So, I redid it using a larger container and a makeshift spray nozzle. I didnt have a larger jar that I could find. Therefore, I used the top section of a 100 disc cd container and siliconed half of a clear CD case onto the bottom. The case has several holes drilled in it to allow flow but still keep 99% of the Co2
inside the difuser. I figure it will diffuse 100% but we'll have to wait and see.
Keep in mind that this is not the prettiest thing in the world. However, I dont intend to use it more than a few months. After which, the plants should be grown fairly well and I will be able to reduce lighting and do away with the Co2
The typical top of a CD container.
$20 Marineland submersible pump.
Drilled a 5/8 inch diameter hole for the input hose.
Drilled three 3/16 inch holes. 2 for the airline suction cups I had left over. And one for the Co2
My makeshift spray nozzle. I used a small section of 1/2 inch copper pipe. I crimped one end nearly flat with a pair of pliers and then drilled several holes in it. I had to heat the tubing to get it to go over the pipe.
Assembly time. All that is left is to put some silicon around the holes I drilled to prevent any Co2
from escaping and add the drilled out CD case to the bottom.
The finished product. Mounted and running. Really tearing through the air inside the container. You can see the CD case attached to the bottom as well.
Like I said earlier, it's not pretty. But it is functional and cheap. If you're looking for a temporary diffuser for a larger tank, dont overlook those CD containers.