Pulling my hair out over my incubator.

[Sakai]

Yes, I've (now) three thermometers and hygrometers in the bator. Two are calibrated while the other is not (And can not apparently) but is in there anyways.
I've not heard of the salt test. I'll have to look that up.
The thermostat arrives today. I'm excited to get it working. It can control humidity too, but we'll be using it for heat monitoring for now and perhaps buy the humidity set up for it. Might be a smart investment.

 

[Shamo Hybrid]

I would go with a bigger light bulb. Do a test run with water, if it's still acting the same then I would only add very few water for humidity in it's first 18 days. Like someone mentioned, after 18 days the chick is pretty much developed and can survive with a bit less heat. Also make sure you have plenty of holes in your incubator so you can control temperature better.... opening and closing of the holes.

 

[Sara L]

You may want to see if you can rearrange your setup in the incubator, at least after the new thermostat arrives. If you only have one light bulb, there's the danger of having no heat at all of the bulb burns out. Since you have a 40 watt and were thinking of increasing the wattage, maybe two light bulbs at 25 watts each, so total wattage only increases a little? Are your thermostats set up to read the air at egg level?