Hello, I thought I'd revive this, as I followed these directions (with a few modifications), and I took photos along the way.
-Co2 will lower the pH of your water, especially in a tank with low kh (buffering capacity). Water parameters must be carefully monitored after adding co2
-DO NOT use a glass bottle. The gas can build up in the bottle, especially if there is a blockage in the tubing, causing an explosion. Plastic can expand and will be more tolerant of increased pressure. Also, if the bottle explodes, plastic will not become the dangerous shrapnel that glass will be.
Drilled a hole in cap with my Dremel to fit the tubing:
Put anti-siphon valve in CO2 resistant tubing:
Put tubing through hole in cap about 1/2 inch:
Seal around hole and tubing in cap (I used a hot glue gun):
Here's the tubing all connected:
I decided to test out a co2 diffuser which I ordered on ebay for $2 (not including shipping), many diffusers will not work with DIY systems because it's not pressurized, but this one is advertised to work:
Add one cup sugar:
1 Teaspoon yeast:
1 Teaspoon baking powder:
Add warm (not hot) water:
Leave a few inches of space for the gas:
Add to tank!