The carboy should have a bung with a drilled hole for an airlock. It should be always covered with the bung and airlock when beer is in it. I wouldn't bottle from the carboy- that's a real pain. It's easiest to bottle from the bottling bucket.I have a fermenting bucket and a 5 gallon glass carboy. I also have a bottling bucket. my last batch came out great, with just the buckets. I received the carboys as a gift and was planning to use it with my new brew. However my carboy doesn't have a cap and my concern is when I transfer the wort to the carboy does it need to be air tight and kept in the carboy for a period of time?? Or do I just transfer the beer to the carboy during the introduction of the priming sugar and then bottle??