Hey guys! So we just upgraded our BP to a bigger tub since he'd outgrown the previous one. We're having trouble keeping it adequately heated though. We have an UTH(with a thermostat) and a 100-watt overhead bulb but it's just not getting hot enough. So here's the predicament.

If the lamp is over the hot side, the temps there are great: 85-90 degrees. But that makes the rest of the tub fall to low 70's.

But, if the lamp is over the middle of the tub, the whole tank gets an acceptable ambient temp of ~77, but the hot spot drops to about ~83.

I currently have the lamp's dimmer off, and the UTH is set to 99 degrees(but because of the thick plastic, somehow a lot of that heat is lost).

Anyone have any suggestions?

Currently we're thinking these are the only two solutions:
-Get another heat lamp(would prefer not to, for the power bill and cost of the lamp itself, things are very expensive up here)
-Pack insulation around the edges of the tub. We plan to pick up some Styrofoam insulation asap to try this.

Some images:


(The foil is to try and help focus the heat lamp more directly)