Please note this tank will be for a lizard that has a basking spot during the day.
The UTH is just for supplemental night heat & doesn't cover a full third of the tank. However installation is the same.
Pictures are thumbnails, click them and they will open bigger.
My supplies. UTH, aluminum foil, aluminum heat tape, thermostat, thermometer & not pictured Blu-tack (for sticking down the probes & wires).
I do not stick my UTH's to the tank like the directions say. I peal off the back and stick aluminum foil to the sticky part of the UTH.
It makes it so I can remove the UTH from the tank if I need to, but you can certainly just stick it to your tank.
The aluminum foil goes towards the bottom of the tank, and I tape it to the tank with aluminum heat tape.
And from the inside
Thermostat probe.
Not pictured, I used Blu-Tack to stick the wire up the side of the tank & the thermostat unit is hanging under the tank.
Thermometer & thermostat probes
The thermometer does 2 temp readings, one from the probe and the other from near the unit, so I set the unit on the other side of the tank. I can see the temp gradient of the whole tank at a glance. If you use a single read thermometer you could hang it on the back wall of the tank or run the probe wire out of the tank and hang it outside the tank.
Here the probes wire is a mess.
A few twist ties and it's all neat
A bigger picture with neat probe wires
With some more tank accessories added. There will be a hide in front of the wire bundle