I've been lurking here for a while and using the search, gleaning a lot of good info from you folks. I'm not new to incubating, but it's been awhile. I've got two of the older Bators with turbo fan and egg turners. Prior to last week, the previous hatch was 20 years ago. With the thermometer that came with these units I'm surprised I was able to hatch anything!! So, my questions are as follows: If I were to swap out the wafer for a new one, would I be better off with a new switch as well? I've got the wet bulb reading well enough, but I'm getting some larger swings in temp reading from my Brinsea thermometer. I've tried covering the top with a towel, but still larger swings. I've ordered a ReptiTemp 500 and will see if this helps at all or if it all starts with the 'stat and the ReptiTemp won't improve anything. I would gladly accept advice from those who've been here, done that. I also saw that one person suggested to add rocks to those spots not filled with eggs to even out the temp. I understand how that would, but with a fan is it really necessary? Shouldn't the bator keep an even temp regardless? I did hatch out 12 of 20 Black Star last Tuesday, would have had 14 but one didn't make it past pip and the other was a breach. Knowing what I know now from hatching way back when, I'd really like to hammer down these other variables and get a little better hatch rate, knowing that sometimes it's the stock, how they were fed, ect, but when you get them to day 20 and no dice, I keep thinking that it's something that I can improve upon. Thanks for your feedback, Jason.