I'm breeding quails in a home made incubator, and can't seem to get my hatch rate above 30% Noticed the following: ---It used to be 50% when I had just a few eggs, but increasing no. of eggs, dropped hatch-rate from 50% to 25% I have done the following to improve: ---Increased ventilation ---Kept humidity & temperature at optimal levels ---Consistently turned eggs a number of times daily (manually) ---Kept incubator disinfected !!! But I just can't seem to get it above 30% !!!! I suspect it's: ---oxygen levels Any other suggestions?