my CO2 setup is like this :
using Mountain dew soda bottle, and I used my old customized bottle cap to connect the airline tubing which I used once for hatching shrimp eggs. Then airline connected to a valve to control the bubble, and then to a check valve, once I forgot to fully open the valve after changing the solution, and then...... arrrgghh!! the valve didnt hold the airline tubing well, so the solution squirt up to the ceiling of my room, and then splash some on my computer! dude luckily the solution is a mix of sugar and yeast, somehow it didn't affect my computer, : ) anyway just a reminder if you connect your CO2 to your canister filter and the amount of the CO2 coming to the filter is strong, it might cause your canister to stop working since to many air coming in than the water.