Which temp do I need to worry about?

[Neville]

So I had my thermometer probe on the floor (slate tiles) and it read 90-91.
I recently moved the probe up by and inch and the temp now reads at 85.
So the floor is 90 and the air around the heated side is 85 (cool at 76).
Is 85 too low for the day? Or is it ok because the floor is constantly at 91?
(cage set up is a 15G L w/ small UTH)

 

[Dog Shrink]

From what I understand it is the temp that is directly on the floor that is most important. The slate will distribute the heat more so than say if you had vinyl tiles so the heat won't go up rather it will go out providing you a larger hot surface rather than elevated ambient temps.

 

[fl_orchidslave]

There is a definite variance between floor and ambient temp. As long as you keep the floor within range its fine. You may need a larger pad for winter since a 15 long has the same floor space as a 20 standard to distribute heat for proper thermoregulation. As it gets cooler it woul be a good idea to keep the probe taped down to the floor to monitor temps.