What's the difference between UVA light and UVB light?

Question

I just inherited a 10 year old iguana. She is just about 3 feet long. I am trying to get the proper lighting set in her new terrarium. I don't know the difference between UVA and UVB lighting? Which is more important for the tank? I also see that you can get different numbers of UVB lighting, (ex./ 5.0 UVB, 10.0 UVB etc...) Is it the higher the better? or the lower the better? Lastly, which is better - the long (old style) flourescent tube lighting OR do I want the newer styled "screw-in" self ballasted flourescent lighting? Please help an iguana "novice" out. Thanks so much

Answer 1

UVA and UVB are two types of ultraviolet light. Ultraviolet B occurs between 290 and 310 nm and exposure to this wavelength is the most important one for your iguana and all basking reptiles. This exposure (normally from the sun) triggers the synthesis of vitamin D3 which in turn allows the body to effectively absorb calcium from the diet. Calcium deficiency is the most common health problem for captive iguanas. Your very best source of UVB is unfiltered sunlight ie. not throught glass or plastic. The two main artificial sources are the fluorescent bulbs you mentioned ( both tube and compact style) and the mercury vapor bulbs designed for reptiles. The mercury vapors are screw in and self balasted as well but look like an incandescent.They produce far more UVB then the fluorescents and for much longer,they also produce heat. If your set up can accomodate it I would recommend one of the mercury vapors. The next choice would be the highest number UVB fluorescent tube rather then the compact.
Because iguanas see in the UV range, UVA effects how food appears to them and can effect their feeding and other behaviour so while important it is far less critical then UVB.

This is the most comprehensive site for iguana care on the web, you are going to have alot more questions.

http://www.anapsid.org/

Answer 2

For an Iguana you must have a UVB bulb--it is full spectrum and imitates the sun. Reptiglo 8.0 or Reptisun 10.0 are the best. The number refers to the amount of UVB produced. Iguanas need a higher number. They are kind of expensive, but vital. Also, they must be changed about every 6 months, as they lose potency--even though they will give off light for a long time. Don't use the coil screw in kind, they generally do not give off enough UVB. Use the long tubes and you'll need a fixture for it. It needs to be within 12 inches of the basking area. She'll need about 10-12 hours of UVB a day. While you're at it, don't forget a heat lamp. I just use a reflector dome and a regular 100W lightbulb. Use a digital indoor/outdoor thermometer to measure temperatures--they come with a probe on the end and when you set it to "outdoors" you'll get an accurate reading. Igs need a basking temp of about 100F all day (placed next to the UVB) in order to warm up enough to digest their food.

As far as "tank" you mentioned, Igs pretty much need to be in large cages and most people end up building their own. They should be about 1 & 1/2 times higher than the Ig and at least as long. They like to be up high to bask. They also need a lot of ventilation, and a tank will become too hot and humid.

They also need a large pool (a rubbermaid storage container or large litter box works well) in order to bathe in every day. Ig's really love to poop in their water (which is quite normal, in fact it helps them to go), so keep it very clean.

If you need more info, go to www.anapsid.org. It is the best Green Iguana site around.

Answer 3

Leopard geckos are nocturnal, so either UVA or UVB can actually be harmful to their eyes. Get an Undertank Heater and use a red night time bulb for him. My daughter volunteers at a local reptile rescue center and we have 2 leopard geckos she brought home. This is what we use for them. The red doesn't disturb their day/night cycle, but just adds enough warmth.

Answer 4

UVA is a longer "wavelength" light meaning that it is effective at longer range and I suspect it will cost more than the medium wave UVB light. Truth is, you are likely just fine with either one. You can use strip or bulb, based on the style of containment and how much coverage you want in the terrarium. You don't want it so that your iguana can't get out of the uv and cool off for a bit, so you don't really need the strongest light on the market. Make sure he has a place to hide away and enough coverage for his whole body. In that case bar length light gives the best coverage, but, you can still make it work with a bulb in a pinch. I suggest a trip to Kingsnake.com for the best reptile assistance on the net.

Answer 5

Hmm... I have never owned an iguana but I know people who have... I would get a round screw in one with a special reptile fixture and put it over a basking spot... I'm not sure which would be better, but you could always get one with both...

Sorry I couldn't help more...