ok, so I guess I had taken it for granted that I woudl put an airlock on top of a starter for liquid yeast. However after reading up a bit, it seems that that is not the standard practice. I live in the caribbean where its hot and close to the water, no air conditioner, so the balcony door opposite the kitchen stays open much of the time. Therefore, it scares me doing just a piece of foil over it for bacteria, dust, and/or bugs getting in. What about removing the airlock periodically to swirl it and let oxygen in? Or does using the airlock make the whole effort of a starter pointless?
by the way, I would do the starter in most likely a liter sized empty liquor bottle, I have a stopper that can fit the top.