Planted Tank Guru
Join Date: Jul 2008
Location: East Lansing, MI, USA
Cut a piece of cheap disposable chopstick about an inch long. Shove it into the end of your CO2 line. You'll have to use an airline holder or weight to keep it down. The gas diffuses through the wood grain and makes fine bubbles. Limewood air stones (usually used in saltwater tanks) work as well but cheapie chopsticks are cheaper. ;-) When you notice fewer bubbles off a fresh CO2 bottle cut off the end of the airline with the old wood and shove another piece of 'fresh' chopstick in.
Kudos to the person who figured this out.