My daughter is using her new Hova-bator 1602-N to do her school science project. She got 24 eggs from a local seller and put them in the bator on January 1st. They were all laid either on the 31st of Dec. or the 1st of January. She split them down the middle and washed 12 of them, her experiment is based on whether washed or unwashed eggs will have a better hatch rate. We have not had any luck trying to candle them so I was wondering how long it takes for the eggs that were no good to start smelling or showing somehow that they are bad. It's been 9 days now and none of them are showing any signs that something is not right. Also I think I might have to go out and buy a good flashlight for candling. We have tried using regular lightbulbs over hoods and camping flashlights with cardboard on top of both and nothing seems to show anything. Is there a brand of flashlight that works best? The incubator so far has worked like a dream, holding the right temperature and humidity and she is religous about turnin the eggs so hopefully we are doing everything right.