I need to hatch quite a few replacement pullets this spring and am thinking of getting a second incubator to use as a hatcher. My question is how frequently should I set eggs in the incubator so that I will get a chance to clean out the hatcher between batches. 7 days seems longer than I need. The laying flock includes 12 hens who lay about 9 eggs each day so I have more that enough eggs to move them through as fast as wisely possible. I know that continually filling every empty space in the incubator would maximize the number, but I think I want to clean the hatcher between hatches. What system do you folks use?