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UV Lighting for Green Iguanas
(& Other Basking Lizards)
Picture of Megaray Bulb

Iguanas and other basking lizards require UVB lighting. Without it they will die of Metabolic Bone Disease. The UVB is what allows them to metabolize calcium in their diet. There are several ways to provide UVB such as:

  • Unfiltered Sunlight - By unfiltered we mean not through glass or plastic
  • Fluorescent UV Tubes - such as ZooMed's Reptisun 10.0 provide UVB with little to no heat. They need to be combined with a heat lamp for heat.
  • Mercury Vapor Bulbs - provide both UVB and heat. These are more expensive but are an all in one solution.

Many people think they can get around the "expensive UV lighting" by buying cheaper aquarium or plant lights. This simply does not work. You get what you pay for and you will have to spend some money on UV lighting unless you live in a climate where you can get your lizard out into unfiltered sunlight for most of the year.

Some people think that by feeding their lizard lots of calcium and Vitamin D3 they can avoid the expensive lighting. This is also untrue. We have seen many cases of MBD because of this faulty information.

Regarding UV:
  • UV only travels so far. When using fluorescent lighting make sure the animal basks less than 12 inches away. Move the basking spot if you have to.
  • Mercury Vapor Lamps are better. The UV from the mercury vapor type lamps does travel further, up to 2-3 feet. Check the documentation for your specific bulb to see how far the UV travels.
  • Remove any plastic or glass covers from fixtures, hoods or the top of the cage. UV will not pass through these materials
  • Replace fluorescent UV lights every 6-12 months. Although they will continue to give off light for years the UV output diminishes rather quickly over time.
  • Larger openings are your friends. When purchasing a screen top aim for the ones with bigger holes. The fine mesh ones block out a significant amount of UV
  • UV Meters are helpful. If you can afford it, purchase a UV meter such as the "Solar Meter". These devices allow you to measure exactly how much of the UV spectrum is coming off your lights (and the sun.)
  • The sun is your best source of UV. Use it by getting your lizard outside as often as possible during the warmer months
What not to do in regards to UV:
  • Do NOT put your lizard outside in a glass tank. This is a sure way to kill an animal. Glass tanks heat up very quickly. Invest in a wire cage made for lizards or ferrets. Wire Rabbit cages work well for smaller lizards. Make sure it is secure.
  • UV doesn't pass through window glass therefore putting your lizard's tank in front of a window will do nothing but possibly heat up the tank to a dangerously high temperature.
  • Tethering your lizard outside unattended is a bad idea. Other animals might come along and injure or even kill them. They can also get tangled up and choke to death.

To recap, UV is extremely important to the well-being of your Iguana and most other diurnal lizards. Don't skimp when it comes to UV. Providing the proper UV is far cheaper than the vet bills if you don't!