Reptile UVB Lighting and Basking Guide: How to Choose Safe Lighting for Reptiles

Frequently Asked Questions

Do all reptiles need UVB?

Not in the same way. The Merck *Important Husbandry Requirements for Selected Reptiles* table and LafeberVet's client handout are aligned: many diurnal lizards and chelonians clearly need strong UVB support, while corn snakes and ball pythons are classified as no-special-lighting-requirement species. Even so, both sources note likely health benefits from broad-spectrum lighting across the board, and Wageningen University & Research's 2020 paper confirms that leopard geckos can synthesize vitamin D3 from UVB. The honest answer: more species benefit from at least some UVB than the older hobby tradition suggested.

Is a basking bulb the same thing as a UVB bulb?

No. The Arcadia halogen heat lamp documentation and the VCA lighting article are direct on this: a basking bulb mainly provides heat and visible light, sometimes UVA, but it does **not** provide biologically useful UVB. Pair basking heat with a real UVB source, or use a manufacturer-spec'd mercury vapor bulb that delivers both.

Can I use an LED bar instead of UVB?

Not as a default. LafeberVet's technical PDF and the VCA lighting article both treat standard LEDs as a visible-brightness solution, not a UVB substitute. UVB-LED products are an emerging category, but published research has raised safety concerns about their spectra, so they should not be presented as the beginner baseline.

Can UVB go through glass or a window?

No, not in a useful way for husbandry. The LafeberVet technical PDF, the Merck *Providing a Home for a Reptile* chapter, and the VCA lighting article are all explicit: ordinary glass and most plastics block the UVB the keeper is trying to deliver. UVB has to reach the animal directly.

How close should the UVB bulb be?

There is no one-size-fits-all number. The VCA lighting article, LafeberVet's technical PDF, and Arcadia's ProT5 documentation all show that distance depends on lamp type, reflector quality, mesh presence, and enclosure height. Generic rules like "9 to 15 inches" are rough references, not universal answers. For specific lamps, the Arcadia ProT5 documentation publishes UVI-vs-distance figures that beat any generic rule.

If my UVB bulb still looks bright, is it still good?

Not necessarily. LafeberVet's technical PDF and the VCA lighting article both note that UVB output falls with use even when the bulb still appears normal to the human eye. Replace on schedule or verify with a UV meter.

Do leopard geckos need UVB?

They should not be treated like bearded dragons, but the evidence supports UVB use. Wageningen University & Research's 2020 paper confirms that leopard geckos synthesize vitamin D3 from UVB exposure, and Arcadia's Lighting Guide gives example basking-UVI targets of roughly 2–3 for leopard geckos with the cool end at 0. Modern husbandry increasingly uses low-level UVB gradients for them — not the same lamp setup as a bearded dragon, but not zero either.

Should UVB stay on at night?

No. UVB is a daytime input. The Merck *Providing a Home for a Reptile* chapter and Arcadia's heater documentation both treat night heat as a separate problem solved by lightless sources (ceramic heat emitters, deep heat projectors) when supplemental warmth is needed after dark.

When is a UV meter worth buying?

A meter becomes especially valuable when the enclosure is tall, screened, unusually shallow, or expensive enough that replacing bulbs by guesswork wastes money. LafeberVet's technical PDF treats meter use as the cleanest way to confirm real UVI at reptile level — it can prevent both premature bulb changes and underpowered setups, and it pays for itself quickly for keepers running multiple enclosures or sensitive species.