Lighting for senior bearded dragons in brumation

At 11 years old your dragon is genuinely senior, and frequent brumation at that age is completely normal — but it does mean their lighting setup needs a rethink rather than just ticking along on whatever schedule you've had for years. Bad lighting is actually the most common husbandry mistake with bearded dragons overall; incorrect UVB or basking temperatures cause metabolic bone disease and chronic illness that many owners don't recognise until significant damage is done. Before I give you specific advice: what size is the enclosure, what UVB and basking bulbs are you currently running (brand and wattage), and roughly how many months a year is your dragon actually active versus brumating?

Good setup overall — a 4x2x2 with T5 is solid. The 6% is fine for younger animals but for a senior dragon I'd actually step up to the Arcadia D3+ 12% T5. Here's the reasoning: as dragons age their skin becomes less efficient at synthesising D3 from UVB, and combined with the reduced active hours he's getting each year, a 6% tube simply may not be delivering enough. The 12% at the same distance gives him a meaningful boost without any risk of overdose. Keep the tube mounted at the same height — around 35–40cm from basking surface — and replace it every 12 months on the dot even if it still appears to glow, because UVB output drops long before visible light does.

Yes, this is worth adjusting. During active brumation — when he's properly buried and unresponsive — you can drop both light and heat significantly. Reduce the photoperiod to 8–10 hours and lower the basking spot to around 28–30°C rather than the usual 40–42°C. If he's deeply brumating, you can even turn the basking lamp off entirely and just leave ambient room temperature, provided it doesn't drop below 15°C. The key rule: follow his lead. If he surfaces and starts basking, restore the full 12-hour cycle and proper basking temperatures that same day. Don't force him back into brumation and don't keep artificially stimulating him with bright light if he clearly wants to sleep.

A few things matter a lot. First, make sure he's a healthy weight going in — a dragon that enters brumation underweight can lose dangerous amounts of mass over winter. Weigh him at the start and check every 3–4 weeks. If he loses more than 10–15% of his body weight, gently wake him with warmth and offer food. Second, hydrate him before brumation starts — a lukewarm 15-minute soak helps, and you can repeat this once a month even while he sleeps if you're concerned. Third, keep his enclosure dark and undisturbed; frequent disturbance stresses them and can cause incomplete, restless brumation. And at 11, a vet check in autumn before brumation is genuinely worthwhile — parasites and early organ stress are harder to spot once he's dormant.

If your 75w halogen is less than six months old you're fine to keep it. Halogens are straightforward — unlike UVB tubes they don't silently degrade, so you just replace them when they blow. The only upgrade worth considering is adding a simple plug-in dimmer so you can drop the basking temperature easily during brumation transition periods without swapping bulbs. For the UVB, the Arcadia D3+ 12% T5 is available on Amazon UK in 54w for a 4-foot fitting — that's the one to get for your enclosure size. Get the tube only if you already have an Arcadia controller, or the kit version if you need the unit as well.