Reptile & Amphibian Forums

does a uvb light stop giving off uvb rays after a cerain time? and if so how would i be able to tell?
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1 sulcata ( sullivan )
1 russian ( foxy )
3 cockerspaniels (wilbur, charlotte and torre )
1 betta ( frederica )

Hi,
A good UV light has a bluish tint to it, a bad one is white. Awhile before it turns white, however, it stops producing the correct amounts of UVB. Therefore, UVB lights need to be changed every 6 months or so to keep the correct amounts of UVB output.
~Sarah
1.0 Mali Uromastyx (Draco)
1.0 Russian Tortoise (Pookie)
4.5.22 Millipedes (6 different species)

The uvb intensity goes down over time. That's a given.
Here's where it gets dicey.
How much uvb is required?
What frequency of uvb is required?
How much of the required frequency does each particular bulb give off?
What is the rate of decay of a particular bulb?
With all the bulbs available today these questions are basically impossible to answer.
(I didn't address the issure of quality control either.)
So, the choice(?) is yours.
I use the active uv heat bulbs. I've got bulbs that I have been using for over 4 years now. When I take photos under these lights the pictures still have a purple hue to them. I've been told that this is caused by uvb. I've also been told that it is the wrong uvb... go figure.
I guess if you want to be safe, I'd suggest using a mercury vapor light (proven to give off the most uvb for the money) and change it out every year. The one study I saw still shows the uvb after one year with these bulbs is still stronger than the best brand new tube type.
Ed

i have been using a reptisun 5.0 hood light.
i bought it used from a local pet shop.
i had to pay $ 35 for the 35in hood with the uvb light.
do you think just to be safe i should buy a new bulb?
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1 sulcata ( sullivan )
1 russian ( foxy )
3 cockerspaniels (wilbur, charlotte and torre )
1 betta ( frederica )

If that's all you've got it is probably not much good but better than nothing.
Do you have it over a 30 gal tank? If that is the case, I'd suggest going with the 7.0. I would think that would be better and would last longer.
Ed

I have to agreed with Ed. I see better appetite and more activity using a mercury vapor UVB bulb over a Reptisun 5.0. I'm waiting on a replacement bulb from Big Apple, but I've been using a Reptisun in the meantime--which to my great annoyance has also gone out, so I had to buy a Powersun today. Anyway, I do see better results with the active UV heat type bulbs.

Ed, do you use your UVB bulbs on a full daytime (12 hour) cycle? That's what I'm doing for winter.
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Sohni
Northern California

0.1 Baja de L.A. Rosy Boa
0.1 Okeetee Corn Snake
1.1 Rubber Boas
1.0 Leopard Gecko
0.0.1 Hermann's Tortoise
plus my kids' herps:
0.0.1 California King Snake
1.0 Mexican Rosy Boa
0.1 Leopard Gecko

Where I use them they are on a 12 hour cycle.
Ed