I have leos,The minimum size viv i keep mine in is a 2ft and i heat with a heatmat run on a thermostat.food wise they eat crickets,mealworms and locusts.They can have waxworms but only as a treat as they are addictive and you will end up with a fat leo that wont eat anything but waxies.The rule for food size is that the insect should be no bigger than the gap between the leos eyes