At the advice of one of the guys at the local brew store, I put a small amount of StarSan along with water in my airlock (s-bend type)...
Once fermentation started (a rather vigorous initial fermentation)... the starsan and water mixer completely bubbled out of the airlock the airlock empty! This happened twice whilst I was out and about and may have been empty both time for 4-5 hours at a time... could this cause "oxidization"?? Or would the pressure from the CO2 prevent oxygen from getting in at this point?
I have since re-filled the airlock with just water, and it's behaving fine.
Is it really necessary to have sanitizer in the airlock as above, could I use another sanitizer for these purposes, or vodka or some such? Or is this all overkill and water is just fine?