I have a 3 gallon batch of New England type cider going and its fermenting like crazy. I need to figure out how the blow off tube is supposed to be rigged. I presently have a 3-piece airlock with the top and bubbler cap off and a piece of 1/2 tubing shoved over the plastic tube sticking up from the bottom of the airlock. It seems to be working but am concerned that a raisin might float up and plug the airlock since the slots (openings) are so small on the end of it thats inside the carboy. If I buy a piece of tubing large enough to fit the top of my glass 3 gallon carboy how do you fit the other carboy to release the CO2 ??? If its tight enough to work on the primary without leaking how will the other one vent???