A Ferguson Zone is a way of grouping reptiles by the ultraviolet exposure they typically experience and use in nature. It gives reptile keepers a more useful starting point than assuming every species needs the same UVB bulb.
What do the Ferguson Zone numbers mean?
Lower zones are associated with animals using lower levels of UV exposure, while higher zones correspond to reptiles that bask in stronger sunlight. The correct target depends on the species and its natural behavior.
Does buying the right zone guarantee correct UVB?
No. The UV Index reaching the reptile changes with distance, reflector design, lamp output, mesh and other enclosure factors. A zone-labelled lamp still needs to be installed according to its instructions and the animal's requirements.
Why is this useful when buying a reptile light?
It helps answer the real question: not “What is the strongest UVB bulb?” but “How much usable UV should reach my animal at its basking position?”
Pristine Pet Supply currently carries a 24-inch T5 Ferguson Zone UVB Lamp with Zone 2 and Zone 3 options. For species-specific guidance, also see our Bearded Dragon, Gecko, Iguana, Turtle and Tortoise care pages.