Can I put a bearded dragon UVB lamp outside the glass vivarium?

No. The RSPCA notes that UVB does not pass through glass windows, so the reptile UVB lamp should be installed inside the vivarium with appropriate guarding and mounting.

Is the highest UVB percentage always the best choice?

No. Fixture type, reflector, distance, enclosure layout, shade, the animal's needs and the measured output all affect the result. Choose a complete, measurable light-to-shade setup instead of comparing a box percentage alone.

How often should I replace a bearded dragon UVB lamp?

Record the installation date and follow the exact lamp manufacturer's replacement interval. A UV Index meter can help verify output because visible brightness does not prove that UVB output remains adequate.

Exotic Pet Care UVB, heat and daylight setup

Bearded Dragon UVB Lighting Setup: Fixture, Basking Zone & Replacement Checklist

Published: 2026-09-18 · Updated: September 2026

Quick Take

Quick answer: choose the UVB system as part of an enclosure, not as a bulb purchase. A useful setup has a guarded UVB fixture inside the vivarium, a bright basking end, a genuinely shaded retreat, a safe heat gradient, a timer, and a way to check output. Do not choose by a...

UVB Lighting Setup Checklist

Guide Focus	UVB, heat and daylight setup
Key Setup Variables	Fixture position, basking height, shaded retreat, lamp output, timer and enclosure layout
Owner Goal	A measurable, repeatable setup before bringing the animal home

Quick answer: choose the UVB system as part of an enclosure, not as a bulb purchase. A useful setup has a guarded UVB fixture inside the vivarium, a bright basking end, a genuinely shaded retreat, a safe heat gradient, a timer, and a way to check output. Do not choose by a percentage on the box alone.

What this checklist helps you decide

This page is for a keeper comparing a UVB tube, fixture, reflector, guard, timer or UV Index meter before setting up a bearded dragon enclosure. It does not diagnose illness or replace an exotic-veterinarian assessment. The goal is to build a measurable light-to-shade gradient that the dragon can use.

Buy the system, not only the lamp

Compatible linear UVB fixture and tube: use the fixture and lamp together as specified by their manufacturer.
Reflector and secure mounting: aim the useful light toward the basking area without removing the animal's choice of shade.
Lamp guard: protect the dragon from burns and from injury if a lamp breaks.
Timer: keep a consistent day/night routine rather than leaving lights on overnight.
Measurement tools: use thermometers for the heat gradient; a UV Index meter is the most direct way to verify UVB output where one is available.

Build three zones before you bring the dragon home

Basking zone: place the heat and UVB so the animal can use both while basking, while still maintaining a safe distance from hot lamps.
Transition zone: give the enclosure a route away from the brightest, warmest point instead of making every perch equally exposed.
Shade zone: provide a real retreat with lower light and temperature. Shade is part of the setup, not an optional decoration.

The RSPCA's bearded-dragon care guidance describes a photogradient with the UVB source near the basking zone and shade at the cooler end. Its example guidance uses a high-output 10-12% UVB fluorescent tube over up to half of the vivarium, and describes checking for a UVI gradient of 3.0-5.0 at the basking zone to zero in the shade. Individual morphs, enclosure dimensions, fixture type and veterinary advice can change the correct target, so treat those values as a source-specific starting point rather than a universal prescription.

Installation checks that prevent common buying mistakes

Keep UVB inside the enclosure: UVB does not pass through glass windows, so sunlight through a window is not a substitute for a reptile UVB lamp.
Guard every lamp the animal can reach: a guard reduces burn and breakage risk.
Verify distance with the actual fixture: the lamp, reflector, mount, enclosure height and basking surface work together. Follow the manufacturer instructions for the exact product rather than copying a distance from a different setup.
Run the enclosure first: stabilize lighting and temperatures before the dragon arrives; the RSPCA recommends running a new vivarium for at least a week so adjustments can be made first.
Keep nighttime dark: use the timer to switch lights off. If overnight heat is needed, discuss a non-light-emitting heat solution and safe controls with an experienced reptile professional.

Replacement is an output decision, not a brightness decision

A lamp can still look bright after its UVB output has declined. Record the installation date, follow the lamp manufacturer's replacement interval, and check output with a suitable meter when possible. Replace a damaged guard, loose fitting or unsuitable fixture before relying on the system. The RSPCA likewise advises regular output checks and replacement at the manufacturer's recommended interval.

Before you spend more

Write down the enclosure size, the exact lamp and fixture, the mounting distance, the basking surface, shaded areas, typical room temperature, and the reading method you will use. That short record makes it much easier to compare products honestly and to ask a reptile veterinarian or experienced keeper a specific question. A more expensive lamp is not automatically the better setup if it cannot create a safe, verified gradient in the actual enclosure.

When to seek professional help

Lighting and husbandry are only one part of welfare. If a bearded dragon is weak, twitching, has an abnormal jaw or limbs, stops eating, loses weight, or shows another concerning change, contact a reptile veterinarian promptly instead of trying to correct the issue with a new bulb alone.