Ok so first hatch for over a decade in on day 10 and have just candled and apart from a couple of clears and a couple of question marks I have a question about the air sack and humidity. I have a chart that I found on here somewhere for the size it should at 7, 14 and 18 that I am comparing to. i have an octogan 20 older model, not digital or anything, in a turning cradle, I've had the vent half open and one water well full every couple of days and humidity has sat at 20-21% but today when candling I thought the air sacks were too small they were if anything a bit smaller than seven day, should I run it dry for a couple of days and re candle a few?? How long does it take for a reaction to humidity change?? I don't want to kill the little yeepers!!! Please help? I'm in northern England, snow outside, but house is a constant 18c 24 hrs a day, incy in living room with no other heat source neat by. Don't know if any other info would help?