ALL heat sources must be regulated, including the bulb. i used a dimmer/rheostat for my CHE and it worked great as the room it was in had a steady temp. a thermostat is the superior choice for electronic control, however. if the room the enclosure is in has unstable temps, then i'd use a thermostat.

also, lower the hotspot to ~89-90° F. young beeps do better with a lower hot spot temp.