Danian

Reptile heating cable under pots, used like a heat matt. You get them in 6m roles for only 80 bucks and 20w. They creat lots of heat tho ! Suggest putting a tile or something ontop to evenly spread heat. Also look into building a simple solar heater with wood, glass and corrugated roof. Simple cheap and extremely effective when running lights at night to keep temps up along with heating cable