i recently built two large tanks out of a big toy box tht was in my room and turned it into a tank well i had two bearded dragons in their but had to move them out because of the winter because it gets to cold and the floor is concrete which doesnt help either although i had crushed walnuts on top of it is their anything i can do to keep it hotter for them to stay warm especially at night time because i like to keep the lights off i was thinking about setting up a helix and put flex watt underneath but i know bearded dragons cant tell how hot it is underneath and i dont know if it would go threw the crushed walnut please help thanks