BACK WALL HEATED RACK TEMPS?????

I have a back wall heated rack that I know can reach the desired heat for ball pythons due to the wattage of the tape. I seem to be getting low temps however in the tubs. Is that consistent with all back wall racks? I'm wondering because unlike belly heat, which the tubs rest right on, back wall seems to rely on the spread of heat. I want to figure this out before I put any animals inside it. I ran it without a thermostat to see what it could do and placed my thermometer on the bottom of one of the tubs about 3 inches from the back wall of the tub. The temp I got was about 85 degrees, give or take about a degree. That seems to be a tad low...especially for not having it on a thermostat and it going full blast. Am I just looking for the temps in the wrong area? I know ambient air has to deal with that as well, but my room as of now is in the low 70s. The heat and connections are not the issue because this is the second set of heat tape I have used...This time higher wattage....Will someone please unlock the mysteries to back wall heated racks for me?

i use back wall heat for my b.p's as well,i use x2 11inch (wide) X 4ft. long flex watt. heat tape(not directly next to each other,but spaced about 1 foot apart. dont know if this helps at all ? but my back heat is around 87-93 deg. on the back side of the tubs and about 82- 85 in the front.

i use 28qt tubs...for hatchlings to two yr olds depending on there growth rate?

also i make my holes a bit bigger on the back side of the tubs...for me it seemed to get it a tad warmer on the whole inside of the tub,but mostly jacked up the heat on the back about 5 deg. higher than it was with the small holes.

hope it helps a little?

-jayson rafter

thanks I'll try that...I just went out today and bought some styrofoam sheets to insulate the back of the rack too

just out of curiosity...what type of wood or material are you using for the rack?