My son has become facinated with my Hovabator 1588 and of course, it's full, so he spent his b-day money last evening on a 1602N model which was about $44 from the local farm supply store. He has 18 duck eggs (unknown breed) and 2 goose eggs (also unknown breed) which he received Sunday. I let them sit quietly on the counter while I tried to help him put together and regulate the 1602N with that screw control. Talk about a frustrating apparatus! So darling son is excited, we believe the unit is set at 101.5 (still air incubator) and going well. We load the eggs and he heads to bed. Worry-wart-mom rises at 11pm and notice temp has fallen and turn the screw. Arise at midnight, still slightly low & turn the screw. Arise at 2am to 104 temp spike (can you say AAAAAAARRRRGGGGHHH) Lid off, screwing back down, frustrated and scared that I've just ruined his little egg project. Every half hour, I'm up and I'm checking it, adjusting and finally by morning I have a constant temp of 101.5 (again, still air) and nice humidity for ducks (about 64%). What do you think..... did I ruin them with that heat spike? P.S. I now really, really love my Genesis 1588 plug and play unit.