I can't get another brew session to work, is it because i am still half way through my first brew session. First brew session is at second stage.

When i have a regular S shape air lock on my plastic carboy, i need to be very careful when lifting and moving the carboy. The vacuum created when lifting sucks the water into the carboy and into the beer. Worried about possible infection, now i put vodka in the air lock. Does anyone else have...