Green Iguana UVB: Why Getting It Right Is Life or Death

The Most Critical Variable

More green iguanas die prematurely from inadequate UVB exposure than from almost any other cause. Metabolic bone disease — resulting directly from chronic vitamin D3 deficiency — is the leading cause of preventable early death in captive iguanas.

The Right Bulb

You need a T5 HO (high-output) fluorescent UVB bulb rated at 10.0. Lower ratings are not sufficient. Use linear T5 HO only — compact spiral UVB bulbs are not adequate for green iguanas.

Replacement Schedule

Replace your T5 HO UVB bulb every six months on a fixed schedule. UVB output degrades significantly before the bulb visually burns out. A bulb that still looks lit may be producing little to no UVB.

Basking Duration

Your iguana should have access to its UVB source for a minimum of six hours per day. Outdoor enclosure time when weather permits is enormously beneficial — unfiltered sunlight provides UV intensity that indoor lighting cannot fully replicate.