Does my incubator need to be completely filled with eggs?

No it does not! Whatever model you purchase, you do not need to set the highest egg capacity for your incubator to properly function. With CT models, make sure to fully assemble and leave your setting trays inside. They do not have to be plugged in and functioning if they are not holding any eggs. When it comes time to hatch, just swap out the trays with as many hatching baskets as you need. Whether you are setting or hatching, it's important to leave all of the parts and pieces inside the incubator, including the humidity tray! Our incubators are specifically calibrated for every included part or piece.