Bearded dragon lighting in a hot conservatory

A sunny conservatory actually sounds ideal until summer hits — direct sunlight through glass can push enclosure temps well above 50°C, which is genuinely fatal. Before we get to that though, bad lighting is the most common husbandry mistake with bearded dragons full stop. Incorrect UVB or wrong basking temperatures cause metabolic bone disease and chronic illness that owners often miss until serious damage is done. So let's get both sides of this right. What size is the enclosure, what UVB and basking bulbs are you currently using — brand and wattage — and how old is your dragon?

Right, a few things here. The ReptiSun 10.0 T8 is a decent bulb but it's underpowered for a 4x2x2 — T8 tubes have weak UV output and at 18 months she needs strong, consistent UVB across the full length of the enclosure. The bigger immediate concern is the direct sunlight. Glass and polycarbonate filter out nearly all UVB anyway, so it's not giving her useful UV — it's just adding radiant heat on top of your basking bulb. On a hot summer day that enclosure could hit dangerous temperatures very quickly. Can you tell me roughly how hot it gets in there in July or August, and do you have any way to measure the basking spot temperature right now?

Panting and hiding is a dragon telling you she's heat-stressed — you were right to move her. 42°C basking is good, but if ambient conservatory temperatures are climbing into the high 30s you lose all control over the cool end, and that's where real damage happens. She needs to be able to thermoregulate by moving away from heat. Here's what I'd recommend: switch to the Arcadia T5 Pro Kit 12% — a 39W T5 HO tube in a reflector hood. It gives genuine, measurable UVB across the full 4ft enclosure, which your T8 simply can't match at that size. The key advantage for your setup is that it runs cool. You can then dial back your basking halogen slightly to compensate for the extra ambient heat in summer, or put it on a dimmer thermostat. The T5 Pro Kit is what most specialist keepers use and it's the single biggest upgrade you can make for her long-term bone and immune health.

Yes, a few practical things. First, put your basking halogen on a pulse proportional thermostat — the Microclimate Evo Lite is reliable and affordable. It will reduce the basking bulb output automatically as ambient temperature rises, so you're not adding 100W of heat on top of a 35°C conservatory. Second, use a reflective thermal blind or shade cloth on the conservatory roof panels above the vivarium during the hottest months — this blocks radiant heat without blocking light into the room. Third, keep a digital thermometer with a remote probe at the cool end of the viv, not just the basking spot. As long as your cool end stays below 30°C she can self-regulate. Those three things together should make the conservatory workable year-round without having to relocate her each summer.

Good question. In summer you can let the natural light cycle guide things a bit — 13 to 14 hours of light is fine for an adult. Just make sure your UVB tube is on a timer that matches your basking light, and switch both off at night completely. Don't let the UV run longer than your basking light — she should never be getting UV without warmth, as that's not how it works in nature. In winter when the conservatory is dimmer, keep the timer at 12 hours minimum. The Arcadia T5 12% is the right call for her age and enclosure size — she'll thank you for it within a few weeks. You should see better colour, more activity, and stronger feeding response once her UV levels are actually adequate.