I found some old tiles and I've cleaned them properly, got a big glass vivarium. So tiles as substrate and a heatpad underneath the glass, will that get too hot? Or should put something underneath the tiles? Someone said told me the other day that I should put pennies between the glass and the heatpad but what for? Getting a Leo that was born in the last breeding season.
You shouldn't have to put anything under the tile. If you're having a problem where the tank isn't heating up enough with the UTH then you may need to add in sifted play sand under the tile (very thin layer) just so it takes out the air pocket under the tile so the heat can be better conducted through the glass and tile to heat up the tank
