# Uvb for adult tortoise



## Raymo2477 (Oct 1, 2016)

How important in daily uvb for grown tortoises?

My adult Hermann's spend May through September outside, do they need a uvb light in fall/winter?

I used one last winter, but noticed no real growth in my juvinile (2-3 year old) torts until they year back outside. I could see noticeable growth after a month outside.

Just wondering home much uvb light is needed for mature (10+ year old) torts? If they're not growing do they need the uvb light?


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## dmmj (Oct 1, 2016)

as long as they're not hibernating they need UVBW, once they're adults for basically good bone development


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## wellington (Oct 1, 2016)

A member that lives up in Michigan does not provide artificial UVB during the winter months. However, I don't know what all species she had and if she provided for some and not others.
Last winter I used regular incandescent bulbs for part of the later part of winter.
This winter I am going to use the incandescent for their basking and will run a UVB bulb for one day a week.
No, they don't need it every day. Even in the wild every place has a few days where it's just gloom and doom. Not sure if anyone knows how much or how little they can live with, but if the member I mentioned above can do without for a Michigan winter, and had no problems, then cutting it down shouldn't hurt either.


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## Tom (Oct 1, 2016)

Raymo2477 said:


> How important in daily uvb for grown tortoises?
> 
> My adult Hermann's spend May through September outside, do they need a uvb light in fall/winter?
> 
> ...



Yes. Adults need UVB too. They cannot assimilate calcium from the diet without it.

No one knows how much they need or how often. Our Michigan moderator didn't use it over winter, but that is a sample size of one. I'm not willing to bet the farm on that. The safe bet is to simply buy a UV tube and run it daily over winter. What would be the reason to not do this? Save a few bucks? As an added benefit, it will also help convince your tortoises that its not winter and they don't need to hibernate.


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## Raymo2477 (Oct 2, 2016)

I was just wondering if there was research about this. I still play on using UVB.


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