My daughter recently built a home made incubator. She is only 10 but did a decent job. Out of the 12 eggs she got 9 fertile ones. Out of those, she got decent growth all the way to day 18. At that point we only saw growth in 5 of them. Out of those only 3 were still alive in the eggs on day 21. One came out on schedule, the other two did not pip at all. She had a great experience, 1/12 eggs on a home made incubator spending 0.00$ on it. She was proud, but wanted more. We bought her a hovabator and an auto turner to start hatching more at a time, on a more consistent temp control, and humidity reading. 42 eggs went in, not so randomly selected from our various chickens. She wanted to candle at day 5, so we did. Looked bad for the brown eggs, but all the white eggs looked good. (I am not sure if the browns didnt look good because they are brown and harder to candle) Then on day 18, from the auto turner to the screen we candled once again, only to be let down by the number of eggs that had growth. Most had none, no veins, no movement. About 8 of the eggs looked to be possibilities, and only 5 were for sure doing well, with good movement, and veins. so.... Day 21 was here and gone, and she was worried about them. No chirping, no rocking and rolling, and no PIP! She asked if she could candle once again, and I said yes. Looked to be no movement in any buy one. SAD DAY As this is the night of day 21... I am wondering if anyone with more experience can help to figure out what we are doing wrong... Anything.. Here are the details I can give. Hovabator foam incubator with a 42 egg auto turner. We start eggs early in the first day. so that lat on day 21 we hope to see something. We keep humidity at 45-50% from 1-18, and 65-70% from 18 and on. We candle at day 5, and candle again when we move the eggs to the lay down position. We do not turn the eggs after day 18. We put all eggs in pointy end down in the auto turner. We do not wash the eggs other than a quick wipe with a damp towel right before we incubate. We keep the box set to about 102 and it stays there pretty well. We use a stick thermo, we have an internal one that sits inside, and there is one on the box (that is not acurate but consistant) My Daughter hatched one chick from her last batch, and has fallen in love with the process. So far she is let down. she did the math and is sad. We should by all reason have a nice batch right now, and we do not. I want to continue hatching my own eggs. But have so many questions about what we are doing wrong. Help me please, as I do not want my daughter to lose interest in something like this, as she is so smart, and this is such a great outlet for her. We have over 100 chickens with mixed batches of roosters, and most our eggs are good to go. I just need to fix whatever it is I am doing wrong... Should I maybe lower the temp a few?