Perfect. You caught me at feeding time. So while hes out of the tank, a side mounted panel is how i heat my tank. Yes you will need to modify the top and insulate at least the back of the tank. I have just a piece of solar insulation over my pad. Its the size of the side of my tank.
Theres a corner rock hide burried in the pothos and wood. So the side panel heats the soil there and provides a warm belly.
Stats set at 90 and stays there. The analog gauge probe is on the mat and i have a digi meter i moved next to the temp probe. Keeps my ambient around 85 with nothing but a dual t5 fixture. One grow light one uvb.
I made the lid dirt cheap. It changed the whole game for us and made life easy. I know i know water dish is dirty. Cleaning it now lol. Hes forever knockin fern leaves into it.