I've started incubating my own pekin duck eggs. I reached the 7th day. Most eggs started to grow veins and heart. My incubator automatically turns eggs. When do I stop turning the eggs and bring up the humidity to 70? A few people say after the 18th day and some others after the 25th. Which is correct? When should the egg loose the 14% of it's water? I ask because I try to control the air sac inside by measuring the weight of the egg daily to allow the appropriate humidity.