Reptile & Amphibian Forums

Since I started reading these forums, I've seen a great number of threads concerning how much UVB certain typs of lights or bulbs produce, and how much, if any, UVB bearded dragons actually need.

From what I've gathered so far, even the best lights are rather weak compared to natural sunlight.

I've also read that glass and some plastics filter out UVB to some degree, but I can't help but wonder how much. After all, every UVB light I know of is made of glass, and the UVB radiation certainly seems to get through it. What kind of glass is it?

Is it possible that even filtered, natural sunlight is equal to, if not better than the best MV bulb?

I know people here either are testing or have tested certain UVB-emitting lights, but has anyone ever bothered to check plain old sunlight coming through a window? Or the inside of a glass tank sitting in front of a window?

It would be almost funny to find out that my dragons here, sitting in the window, are getting as much or more UVB as they would from the most expensive Mercury vapor bulb.

D.A.

Glass filters out almost all UVB rays, plexi glass filters out about 65 percent. MVB are said to be equivilent to being in the shade. Nothing beats natural unfiltered sunshine, but where I live that is only an option in the summertime.
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It's my understanding that some types of glass filters out more UVA/UVB than others.

My question then is: What's the difference? What is it in the one that is not in the other? Lead? Zinc? What?
Is there any type of glass that blocks no UV at all?

It's very possible that if I can find a glass or plastic that could be used as window glass, that doesn't block UVB, I might very well change out at least one window in my house for the lizards to bask in.

D.A.

The glass in light bulbs and greenhouses does not block UVB at all.
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What I've found so far is that ordinary window glass is pretty much opaque to wavelengths below 3,000 angstroms.
What I haven't found yet is what the range is for UVB, in angstroms... grrrr.

Also, quartz glass is UV-transparent. But I have no idea where to find it, or what the cost is.

D.A.

UVB radiation is from 320 - 290 nanometers.

or 3200 - 2900 angstroms.

>>UVB radiation is from 320 - 290 nanometers.
>>
>>or 3200 - 2900 angstroms.

Which means that at least some UVB passes through ordinary window glass.
Not much, but at least what's on the higher end of the UVB spectrum.

I keep reading here and there that it's the amount of iron in the glass that filters UV. Even found one site concerning building a greenhouse for a school. The glass panels were 1.5 meters square, and transparent to UVA and UVB.

Too bad they didn't mention where they were getting their glass, or what it was called. ( It wasn't quartz, it was low iron content )

D.A.

n/p

my understanding is that leaving a tank in front of a window allows to much heat to get trapped in the tank
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proud mama to:
1.0.0 ball python (mr snake),0.0.1 albino florida kingsnake (CK),1.1.0 leopard gecko (sebastian and vilma),0.1.0 colombian rainbow boa (luce),1.1.1 bearded dragon (kaipo, dulce, and kellen), 1.1.0 colombian redtailed boas (adam and eve)

I have two tanks in front of windows.
82 to 85 degrees on one end, 94 to 96 on the other. Basking site stays between 105 and 110 degrees.

But then, I'm home most of the day to keep an eye on things too.

D.A.