You'll have to excuse me I misused the term ambient. I did MEAN the surface temp. I had thought ambient referred to the average temperature of that end of the enclosure. My mistake.
And, I dont know what to tell you buddy. I am absolutely working with a 100 watt on my 40gallon, a 100 watt on my 39 or 37(I cant remember which), and 75 watts on my two 20 longs. Im using command strips to suspend the bulbs on the larger tanks aprox. 4-5 inches, and the 75's hang 1 inch above the screen. My temp gun is not malfunctioning, and the surface temps of their warm hides read 89 or 90.
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