hello.if this isnt in right section im sorry.my husband had built a incubator from styrofoam cooler 16"x16"x16" deep as an experiment.as of today we have 8 new chicks and and 4 have pip the shell.out of 17 eggs.he had a 100 watt bulb with a dimmer switch to control heat.3.. 1/2" holes in bottom and 3 on top other side.had a bowl of water in there with a little sponge and it kept humidity at about 50% temp was between 100 and 102 entire time.18th day he put a large sponge in the to get humidity to 65.it took 21 days to hatch.we have a delaware rooster with plym rocks and rhode island reds hens.we want to thank everyone for all the info that was posted to be able to have these beautiful chicks.