UVB light distance

[Gracie257]

Hi all - my first post on here.

I apologise if this has been discussed before, but some of the posts are older.

I have recently bought the pro t5 24w Arcadia kit for my hermann female. My issue is finding the correct information on how far away is optimal for her. I’m moving it so it will be by her heat lamp (as she loves that) but there’s a lot of conflicting info online and I really want to get it right. I have a handyman coming in the week to help me make some adjustments to the table.

I understand as a hermann she is in Ferguson zone 3, so therefore do I want it to be a minimum of 450mm/18 inches from her shell? Any help reading this and making sure I get it right would be greatly appreciated.

Also thank you so much to everyone who runs and contributed to this forum! It’s such a good place for information.

 

[Markw84]

Assuming you are hanging the light with no screen between the bulb and tortoise, the Arcadia Pro T5 12% will be great at 18"-20" - 450mm - 500mm. I install that exact fixture in my enclosures at 20" / 500mm.

 

[Gracie257]

Assuming you are hanging the light with no screen between the bulb and tortoise, the Arcadia Pro T5 12% will be great at 18"-20" - 450mm - 500mm. I install that exact fixture in my enclosures at 20" / 500mm.

Hey Mark thanks so much yes I am hanging the bulb over the top in the reflector. Out of curiosity, do I take into account the tortoises height and the amount of subtract depth when calculating the distance? I may be looking too much into this or is it just 450mm - 500 regardless of that?

 

[Markw84]

Hey Mark thanks so much yes I am hanging the bulb over the top in the reflector. Out of curiosity, do I take into account the tortoises height and the amount of subtract depth when calculating the distance? I may be looking too much into this or is it just 450mm - 500 regardless of that?

Yes. But you don't have to be exact - looking for the 450mm-550mm range from top of tortoise shell to bottom of bulb. Be sure you have a few potted plants in the enclosure to give natural hides and a way to get away from the UV when desired.

 

[Gracie257]

Yes. But you don't have to be exact - looking for the 450mm-550mm range from top of tortoise shell to bottom of bulb. Be sure you have a few potted plants in the enclosure to give natural hides and a way to get away from the UV when desired.

Perfect - yes I have some plants and hides and I’m putting it up one end so she can get ‘out of it’ if needed. Really appreciate your help!

 

[Tom]

Hi all - my first post on here.

I apologise if this has been discussed before, but some of the posts are older.

I have recently bought the pro t5 24w Arcadia kit for my hermann female. My issue is finding the correct information on how far away is optimal for her. I’m moving it so it will be by her heat lamp (as she loves that) but there’s a lot of conflicting info online and I really want to get it right. I have a handyman coming in the week to help me make some adjustments to the table.

I understand as a hermann she is in Ferguson zone 3, so therefore do I want it to be a minimum of 450mm/18 inches from her shell? Any help reading this and making sure I get it right would be greatly appreciated.

Also thank you so much to everyone who runs and contributed to this forum! It’s such a good place for information.

View attachment 397883

Every bulb is different. The distance that Mark suggested should be good, but the only way to know what your bulb is doing in your enclosure is to put a Solarmeter 6.5 under it and check it. This is also how you will know when to replace the bulb. Anything else is just guessing based on what we've seen from other bulbs of this type.

If your bulb is on the weaker side of the spectrum and you mount it at 20 inches, your tortoise will be getting lower levels of UV. If your bulb is on the stronger side of the spectrum and you mount it at 18 inches, it might be making very strong UV. In a warm sunny climate where Mark and I live, our tortoise can get outside for sunshine year round. In your climate, when the tortoise has to be indoors for most of every year, it is more important to get this number right.

 

[Gracie257]

Every bulb is different. The distance that Mark suggested should be good, but the only way to know what your bulb is doing in your enclosure is to put a Solarmeter 6.5 under it and check it. This is also how you will know when to replace the bulb. Anything else is just guessing based on what we've seen from other bulbs of this type.

If your bulb is on the weaker side of the spectrum and you mount it at 20 inches, your tortoise will be getting lower levels of UV. If your bulb is on the stronger side of the spectrum and you mount it at 18 inches, it might be making very strong UV. In a warm sunny climate where Mark and I live, our tortoise can get outside for sunshine year round. In your climate, when the tortoise has to be indoors for most of every year, it is more important to get this number right.

Thanks so much Tom - I’ve read a lot of your responses on this forum and your insights are always really useful, so thank you for this!

Ok that’s great I will look at getting one of those to measure the uvb. I do think my current bulb is on the lower side so this new one will be a whole lot better.

The handyman comes back in 2 weeks to set it all up so in the meantime I will get that measurement and make sure it is as correct as I can. In the summer I will be getting her outside too where possible.

Appreciate it very much.