We had a tank with a mesh top for a few weeks until we got a pvc enclosure. To moderate the humidity in the tank, we put foil over the top, but it was a constant battle. The heat bulbs really do dry things out, but a ceramic bulb might be a bit better. Also, be careful with an under tank heater if you don't have a thermostat regulating it. It's an investment, but getting a pvc enclosure and a quality thermostat (we got a herpstat) has helped a lot with regulating temp and humidity and our time and anxiety. Also, I would advise getting a cheap digital hygrometer from target or walmart instead of the dial ones that come in the tank packages. Just a thought. Oh! And moss. When we had the glass tank with the mesh top we used sphagnum moss to help keep the humidity up and that worked wonders! I hope this helps