I was doing some research, and then did a little of my my own experimenting with a couple little giant incubators. Here is the website page for the research. http://www.poultryconnection.com/quackers/incubator/batortest.html This gentleman decided he wanted to hatch eggs, and wanted to know which incubator worked best. He did a test, which he explains in detail on his page. It is a little dry reading it, but the tail end was the best part. He gave the recommendation of breaking in your incubator by running it for at least one full week before adding eggs. I agree. I have 2 little Giants...one with an egg turner, one with a fan. The one with the fan, even during the breaking in for a few days, has fluctuated only four degrees (99.5-103.5). Not the best...but not egg-killing bad. The humidity has ranged wildly, like a dog its first time on a leash. Anywhere from 20%-90%!!!!!!!!! It is still in the break-in cycle (day four)...no eggs in it...so I am not freaking out yet. The bator without the fan (but with the turner) did FINE in its test run of 10 hours. Almost no variation in temp. So, I put some much treasured and VERY well packaged bourbon red turkey eggs in it. THEN the fun started. The bator ran cold the first day...88-98. Expected, since the eggs need time to warm up. The next day, without adjusting anything...it shot to 105. For up to 3 hours, but i think it was less than an hour. Then, after minor adjustment, it dropped to 95 for up to four hours. You get the idea. Temperature spikes high and then very low...everything in between 88 an 105. Humidity is fairly constant, between 40 and 55. I am still incubating them, they are on day six so hopefully they make it to candling day without exploding (ick). I think maybe I should have just made omelettes, though. Because, at day 5...they have been HORRIBLY incubated with this new machine. Maybe I should have broke it in first, like was suggested. Maybe I am too hard headed lol. Then again, the guy said to break it in for at least a week before incubating any eggs in it for the very same reasons. Please remember to break in your machines...it will save you some heartache. And from having to buy more eggs. And from the stress of worrying about eggs exploding before candling.