Bearded dragon lighting requirements

The requirement, in one table

Everything below is an explanation of a row in that table. If you only read the table, you have the requirement.

1. UVB - the one you cannot substitute

A bearded dragon is a diurnal, open-sun basking, terrestrial desert lizard and sits in zone 3, edging into zone 4 per the Ferguson zone guidance, which is the top end of what the hobby keeps. The target is UVI 4.0-4.5 at the basking surface measured at the basking surface - not at the lamp, and not somewhere convenient in the middle of the enclosure.

That figure drives three decisions. Format: a linear T5 HO tube, because a tube lights a basking zone and a coil lights a point. Output class: 12-14%, because a 5.0 cannot reach this target at a workable mount height. Distance: set by the fixture, the mesh and the published chart, then verified. Mesh costs roughly a third of the UVB passing through it, which is why a lamp mounted on a screen top sits closer than the free-air figure suggests. UVB distance and Ferguson zones has the arithmetic, and best UVB for bearded dragons is the lamp roundup.

2. Basking heat - a separate lamp, on a separate controller

The published target is a surface temperature of 108-113 F (42-45 C) surface temperature per the care reference, and it is a surface figure rather than an air figure - so it is measured with an infrared gun pointed at the rock or platform the animal sits on. A halogen spot is the preferred source, because halogen delivers more Infrared-A, the deeply penetrating band, than a ceramic emitter does.

Wattage is chosen last and by measurement, not from a chart: install the lamp at your mount height, run it closed for 45 minutes, read the surface, adjust. See best basking bulbs for bearded dragons and how to measure basking temperature.

3. A thermostat is a lighting requirement, not an accessory

A basking lamp without a thermostat is a lamp whose output tracks your room temperature. On a cold morning the surface is under the band; on a hot afternoon it is over it. A dimming or pulse thermostat with the probe at the basking surface holds the figure instead, and it is the difference between a published target and a hopeful one. Do I need a thermostat for a bearded dragon answers the question in full; the short version is yes, and it must be the dimming type for a filament lamp.

4. Photoperiod - the cheapest requirement on the list

12-14 hours of light per day, seasonally adjusted as published, delivered by a plug timer that costs almost nothing and removes the one failure mode nobody plans for: forgetting. Both lamps on the same timer, both off together, and a real night with no light at all. If your room drops below 55-75 F (12-24 C), the answer is a lightless ceramic emitter on a thermostat - never a colored bulb. Night lighting mistakes covers why.

5. Verification - the requirement most setups never meet

Every figure above is a measurement, which means every one of them can be wrong in your enclosure while looking right on paper. Two instruments close that gap: an infrared gun for the basking surface, and a UV index meter for the UVI at that same spot. The meter is the expensive one and it is the one that answers the question you cannot otherwise answer - a UVB tube at 11 months looks identical to a new one and delivers a fraction of the output.

Putting it together

A correct bearded dragon enclosure has a linear UVB tube running most of the basking end, a halogen spot at one end above a platform, both on one timer, the halogen on a dimming thermostat with its probe at the surface, and a cool end far enough away to actually be cool. That is the whole requirement. The build order is in bearded dragon UVB and heat setup, the thermal picture in bearded dragon temperature and humidity, and the running electricity cost in reptile lighting running costs.