How much water in the airlock?

Another noob question. I have one of those S-shaped airlocks with two chambers that came with the NB kit. I started with water in both chambers but as soon as fermentation started it pushed the water out of the first chamber. So I’ve been fermenting just with water in the second chamber. Seems like that should be fine as long as the second chamber doesn’t go dry. Any thoughts?

Pressure will keep it noved to one side, just don’t let it go dry. I like to use cheap vodka in mine just in case anything were to get sucked in.

just keep an eye on it. If it gets low, add a little.

Same here concerning the vodka. I buy the cheapest vodka available and keep half of it in a spray bottle for instant sanitizer.