so ive set up my flex watt and my herpostat set my probe taped in the center of my bottom of 2 tier shelf and set the thermostat to 95* (thick sterolite tubs) and my thermo gun is only reading 78* in the tub(hot side)..the room everything is in was around 83*

any ideas why theres so much of a temp difference dif?

and where do i plug in the dimmer switch to make sure it really does its job? before the thermostat or before the powerstrip to the rack?