UVB

Your Iguana needs a basking heat source, usually provided by some sort of light bulb, but they also need a special UVB producing light. UVB helps Iguanas synthesize vitamin D3, which is needed to help metabolize calcium in the Iguana's diet. Iguanas cannot process dietary D3, and require a strong UVB source to help their bodies produce it. Without a UVB source, Iguanas will be unable to process calcium properly, and will be susceptible to Metabolic Bone Disease, an often fatal result of calcium deficiency.

There are several types of UVB producing bulbs on the market. Some of the best include ZooMed's Iguana Light 5.0 and Reptisun 5.0, as well as T-Rex's Active UVHeat bulb and ZooMed's PowerSun. The first two are fluorescent-style tube bulbs that require a special fixture. The second two are mercury vapor lights that produce both heat and UVB. These fit in a regular dome light socket, but produce a lot of heat and require a ceramic socket. Most tube-style UVB bulbs lose their effectiveness in about 6 months, even though they still produce light. The Active UVHeat bulbs last at least a year, and provide heat as well as the needed UVB. Be careful when shopping for a UVB bulb. Many manufacturers advertise their bulbs as 'full spectrum' even though they do not produce UVB. Make sure you purchase a bulb that specifies UVB production. The bulb should state that it produces at least 5% UVB. Read the packaging carefully. Several people have had problems buying lights that state they produce UVB (especially the new coil style UVB lights) but they do not produce enough UVB to keep the iguana healthy. Many of these people are now treating their iguanas for MBD. Grow Lights, lights made for aquariums, and plant lights are NOT UVB producing lights.

UVB dissipates with distance. You need to make sure your iguana is able to get close enough to the UVB for it to be effective. For the tube style lights, they should be no more than 6-8 inches away from the iguana. The stronger mercury vapor bulbs should be about 12 inches away for the floods, and 18 inches for the spots because of their strength and the intense heat they can produce.

Be aware that UVB can be 'diluted' or blocked by many things. UVB rays cannot pass through glass, except for several specially manufactured and rather expensive types. The same thing applies to plastic and plexiglas. Make sure that your ig has access to the direct rays of the UVB light. Screens and mesh can also block or filter UVB rays, so when planning your cage, go for the largest size mesh you can find. Some manufacturers are now selling fixtures with a plastic guard over the light. If you have one of these REMOVE THE PLASTIC! UVB cannot pass through it!

You want your UVB source to cover as much of the cage area as possible, not just the basking spot. A good way to accomplish this is to purchase a 4 foot shop light from Home Depot or Lowes, and use two 4' ZooMed bulbs in it. With the fluorescent style tubes, the first inch or two on either end of the bulb does not produce significant amounts of UVB, so you want to be sure to go with the longest bulbs you can. Also remember to replace your bulbs at least every 6 months.

Another great source of UVB is natural sunlight. If at all possible, get your iguana outside in warm weather to soak up that sun! A sun cage is easy to build using PVC pipes and plastic garden mesh, and lets your iguana roam a bit safely. NEVER put an iguana (or any other animal) outside in a glass aquarium or cage! The greenhouse effect will VERY quickly cause overheating and death. Each summer we hear sad stories of iguanas who have literally been cooked to death in a glass cage. Even when inside, if you have a baby ig in a glass cage, be sure it is out of reach of direct sunlight since overheating can occur even indoors. For sunning, invest in a mesh cage or use a hind end harness and leash. It is never a good idea to allow your iguana outside unrestrained. While outside, watch for signs of overheating - usually a gaping (wide open) mouth. Make sure that your ig has access to shade and water at all times.