I just set up a 16 qt rack and have a question about the temp. I have a Herpstat 1 set at 95 F and a backup Ranco set at 100 F. Is it better to use the digital thermometer in the probe which is measuring air temp or use the surface temp reading using a INfrared thermometer? My air temp is 87 and my surface temp on the hot side if the tub is 89 F.

Thanks