I have two 72-cell hydrofarm mini greenhouses with heating mats, they're hooked up to a thermostat that keeps the temperature at 84-86 degrees. I've had very good results for the most part, but I've noticed a pattern with both of them...the seedlings in the middle don't seem to germinate very well, while the ones all around the perimeter are doing very well. I'm not sure why...the middle seems to dry out a little more quickly, but I've been spraying it frequently keeping it moist. I thought maybe the middle was getting too hot because it was drying out faster, so I moved the probe to the middle and it has stayed at 84-86 degrees, if anything the outside would be less than ideal temperature if it's a little lower, yet I'm getting the same results...the outside perimeter is thriving, the inside is struggling. Has anyone had similar results?