Bearded dragon lighting on a budget

Bad lighting is the most common husbandry mistake with bearded dragons — incorrect UVB or insufficient basking temperatures are the leading causes of metabolic bone disease and chronic illness, and most owners don't realise damage is happening until it's well advanced. Wanting to cut electricity costs is completely reasonable, but the way you do it matters enormously — wrong cuts lead to vet bills that dwarf any savings. To help you optimise properly: what size is the enclosure, what UVB and basking bulbs are you currently running (brand and wattage if you know them), and how old is your dragon?

Good news — there's real savings to be found here, and your dragon won't suffer at all if you do this right. Actually, your current setup has two inefficiencies worth fixing. The T8 Reptisun 10.0 is a decent bulb but T8 tubes are low output, which means it needs to sit very close to the basking area to deliver adequate UV Index — in a 4x2x2 that's often not achievable, so your dragon may already be getting less UVB than you think. Switching to an Arcadia T5 HO 12% 39W tube covers the whole floor of a 4-foot enclosure and delivers proper UVB from a realistic distance. It uses similar wattage to your T8 but does the job far more efficiently — you may actually be able to drop your basking spot to a 100W halogen flood and still hit the 40–42°C surface temp a 4-year-old needs. On photoperiod: 12 hours light in summer, 10 in winter is appropriate for an adult. If you're running longer than that, cutting back saves electricity and is actually more naturalistic. What are you currently running for hours per day?

Yes — 13 to 14 hours is slightly too long for an adult and trimming to 12 hours gives you a meaningful saving straight away, no compromise at all. The Arcadia ProT5 Kit does include a high-polish reflector, which is actually one of the most important components — it nearly doubles the usable UV output compared to a tube without one, so you get more effective UVB from the same wattage. The specific product I'd recommend is the Arcadia T5 HO 6% or 12% ProT5 Kit in 39W for a 4-foot enclosure. For a 4x2x2 with a full-grown adult dragon, go with the 12%. It comes with the controller unit, reflector, and tube. Pair it with a 100W halogen flood bulb for basking — halogen floods are far cheaper to buy and run than branded reptile basking spots and produce the same heat and light spectrum. Between dropping to 12-hour days, switching to the T5 kit, and moving to a 100W halogen, you're looking at a meaningful reduction in running costs and your dragon will actually be better lit than he is now.

Arcadia rates the T5 HO 12% tube for 12 months of UV output at standard photoperiods — after that the tube may still produce visible light but UV output drops below safe levels. Mark the date on the tube when you fit it and replace annually. At roughly 12 hours a day that's around 4,380 hours of use before replacement. The tube itself costs around £20–25 to replace, so the ongoing cost is low. Given that your dragon is 4 years old and fully grown, consistent UVB is what keeps metabolic bone disease away long-term — that annual tube replacement is genuinely the most important recurring cost in his whole setup.

That's a solid plan. To recap: Arcadia ProT5 HO 12% 39W Kit for the UVB, a 100W halogen flood for basking, and dial the photoperiod back to 12 hours. Verify your basking surface temperature with a temperature gun — not an ambient thermometer — and aim for 40–42°C on the spot. If it runs hot with the 100W, drop to 75W; if cool, go back to 100W. Your dragon is at the age where good UVB really pays off in long-term health, and you'll be running a more efficient setup than you were before. Good luck with it.