We also have about 40 duck eggs in the incubator, 20 cayugas and 20 anconas. We already had an automatic turner so the number of turns was not an issue to us. Humidity IS and we are using as our guide David Holderreads excellent book printed by Storey's called Raising Ducks. We have hatched out guineas before with a very high hatch rate but ducks are new to us. This book has an excellent guide that we are using and yes he suggests misting the eggs daily after day 7. One reason he lists for not candling until day 9 is how fragile the brand new embryo is at day 7 AND you may miss one at 7 that you would get at 9. Our Cayugas resulted in 17 out of 20 fertile and the Anconas 14 out of 20. We are trying to keep the humidity in the 50-55 % range although that is difficult in our small air circulated incubator. We keep it close is all I can say. If you can find a Google reference to David Holderread I would trust that one. Good luck and it will be interesting to compare notes!
