Uv index /microwattage

[katrvt]

So, in effort to continue my self-education, I have a curiosity question. I am familiar with 10.0 vs 5.0 in terms of distance it should be placed from the reptile in question, but I'm unsure about uv index and uv microwattage requirements and how much each species type requires. I get the basic mechanics of it, what I'm really wondering, I guess, is specific requirements for each tortoise species, and if they differ, how much so? Or, if there is a place where I can find this information, as my search thus far has come up dry.

 

[katrvt]

Looking through other uvb posts, thinking maybe @mikeh will know the answer?

 

[jaizei]

If you haven't already been there: https://groups.yahoo.com/neo/groups/UVB_Meter_Owners/info

 

[katrvt]

Haven't found that one yet. Thanks

 

[mikeh]

We can make an educated guess on how much UV, in microwatts specific species is exposed to by knowing suns UV output in given environment the species live in and habits of the animals. Arid species will bask in direct sun in the morning and late afternoon or thru out the day on cooler days. Forest species will mostly seek diffused sunlight by forest canopy and shade. Hatchlings will seek less sun then adults.

Direct morning-midmorning sunlight on clear day yields 100-250 microwatts.
Direct midday sunlight can yield as much as 400-550 microwatts in arid climate.
Diffused sunlight and partial shade yields 40-80 microwatts.
Full shade 20 microwatts and less.

We can safely assume that forest species will be exposed all day from 20 to 100+ microwatts. Some will bask in early morning sun getting more microwatts for short period of time.

Arid species will be exposed to anything from 20 to few hundred microwatts. Again, adults more then hatchlings. From my observation of a single 6month old leopard which was housed outdoor full time last year for few weeks in day time temps of 75-85F ....the tortoise would avoid midday sun. It will bask and forage in early morning to midmorning sun, the again in the later afternoon. It received about 100-300 microwatts for about 3-5 hours a daily. Rest was spent in shade(20-30 microwatts)

To translate this to indoor habitat and ideal UVB light output few parameters need to be considered. How much time the tortoise spends under UVB light/ how much of habitat area is covered by UVB. If tortoise spends an hour a day in the UVB coverage higher output may be desired. If UVB light covers most of the enclosure and tortoise is exposed to UVB many hours per day, lower output is desired, but still appropriate for the species. Artificial UVB light produces UVB only mostly directly under the tube/bulb.

In the above mentioned leopards indoor enclosure 50% of the area was covered by UVB tube and the animal spent good portion of the day in that area exposed to T5HO Arcadia 3D+ 12% reading 140-170microwats at tortoise level. This proved to be too much as the skin/scales on the animals head developed some minor UV burns(rough scales) over couple months of exposure. Because artificial UVB does not replicate identical spectrum to sun, the animal can still get burns in lower then suns microwatts. I have increased tubes distance to achieve 100-110 microwatts under the tube.

I think for arid species 100microwats is a safe number with artificial UVB where tortoise spends couple or more hours a day under the light.

For forest species (Burmese brown) I run 100 microwatts as well but the UVB is mostly diffused with plants yielding 20-100 microwatts. In bare enclosure I would make a range of 20 to 80 microwatts from one side to the other by creating a hill or tilting the tube.

 

[katrvt]

Thanks! That is exactly what I was looking for!