Arcadia vs Zoo Med UVB lamps

The verdict, in one paragraph

There is no winner here, and a roundup that declared one would be inventing a difference the evidence does not support. Both brands appear in the care guidance as reliable and approved for use. The bearded dragon guidance publishes Arcadia distance figures directly, which is a real practical advantage if you do not own a meter. The ball python guidance names Zoo Med and Arcadia together as the two brands reliable enough to use without a Solarmeter in hand. Buy whichever you can source, and set it using that brand's figures.

Where they genuinely differ

Why the distances are not interchangeable

A UVB lamp's output at a given distance is a function of the phosphor blend, the tube diameter and length, and the reflector it sits in. Two lamps labeled similarly can deliver measurably different UVI at the same height. That is why the published figures always name the lamp and, implicitly, the fixture: an Arcadia Desert 12% at 11 inches through mesh is a specification for that combination, not a general rule about 12% lamps.

The practical consequence is simple. Pick a brand, use that brand's fixture or a reflector fixture its charts assume, and use that brand's distance. If you want to mix, you need a meter - which is the honest version of the answer.

Pick Arcadia if, pick Zoo Med if

• Pick Arcadia if you want the species distance figures published in the husbandry guidance you are already following, if you keep a Ferguson Zone 1 gecko and want a purpose-built low-output lamp, or if you are buying the fixture and tube together as a kit.
• Pick Zoo Med if availability matters - you want to replace a tube locally in an afternoon rather than wait on an order - or if you already run a Zoo Med fixture whose chart you are working from.
• Pick either, with a meter, if you are mixing brands, mounting inside the enclosure, or keeping a reduced-pigment animal whose UVI ceiling is low enough that a chart estimate is not good enough.