Bearded Dragon Lighting, Without the Guesswork

The temperature gradient

Reptiles are ectothermic: they move between warm and cool areas to control their body temperature. The RSPCA's bearded dragon guidance calls for a thermogradient in the vivarium - a hot, bright basking end at 38-42 degrees Celsius and a cooler shaded end at 22-26 degrees Celsius, regulated by a thermostat. Their advice includes details worth copying: place a natural stone in the basking zone, keep the dragon's back at least 25-30 cm from the lamp, fit the bulb with a wire mesh guard against burns, and check both ends daily with an infrared thermometer rather than trusting the thermostat dial. At night, temperatures shouldn't drop below 20-22 degrees, so a non-light-emitting ceramic heater may be needed.

The UVB half of the equation

Heat is only half the setup. The RSPCA explains that UVB light lets a bearded dragon make vitamin D3 in its skin, which it needs to use calcium - and that UVB does not pass through glass, so a reptile UVB lamp belongs inside the vivarium, not shining through a window. Their specifics:

• Use a high-output 10-12 percent UVB fluorescent tube, up to half the vivarium's length, fixed into the roof at the hot end to create a light-to-shade "photogradient."
• Aim for a UV Index gradient of 3.0-5.0 in the basking zone down to zero in the shade, checked with a UV Index meter. (Albino morphs need lower levels, maxing at 3.0.)
• UV output fades over time - replace lamps on the manufacturer's schedule, not when they burn out.
• Guard UV lamps too, and turn all lights off at night. A simple plug-in timer set to 12 hours on, 12 hours off handles the rhythm.

Why it matters: the RSPCA notes that one of the most common problems in captive reptiles, metabolic bone disease, is most often due to a lack of UVB lighting - the deficiency prevents calcium absorption and can cause muscle weakness and bone damage. Good lighting is not decoration; it's the core of the setup.

Track lamp dates and temps in PawLine

"When did I last change that UVB tube?" is a question with a real cost. You can find an answer in the PawLine app: log lamp install dates, daily temperature readings, and replacement reminders with your dragon's profile, so the schedule lives somewhere better than memory. You can find this in the PawLine app.