UVB bulb 5.0 vs 10.0

[Linhdan Nguyen]

Hi,
So i recently order a UVB tube bulb from pet mountain and I THOUGHT i ordered the 5.0- T8 bulb but my shipment confirmation shows I ordered the 10.0-T8 bulb. I wanted to know the difference (if any) between each to see whether or not I should return/exchange it.

 

[Yvonne G]

I'm not the lighting expert on here, but seems to me I'm remembering a thread a while back where they said the bigger one was better - more and better UVB.

 

[JoesMum]

It depends on your tort. If you have a forest species like a red foot then 5.0 is plenty.

 

[Linhdan Nguyen]

I have a russian. Is there more light that the 10.0 emits? Or the same amount of light, just more uvb? And do I still mount it 12" away from their shells?
I believe someone in another thread also mentioned there was a strong 10.0 uvb that could be used but only 4hrs a day? I dont remember if thats because of how much uvb is emitted or how far the bulb is mounted.

 

[Sara G.]

I'm not sure if you can have a problem where a tort gets too much UVB. I'd like to know for sure if that's true or not.
Usually the box the bulb came in has a recommendation for how far away it's supposed to be. 12" sounds about right though.
And for a Russian I would say that's perfect.

 

[JoesMum]

I'm not sure if you can have a problem where a tort gets too much UVB. I'd like to know for sure if that's true or not.
Usually the box the bulb came in has a recommendation for how far away it's supposed to be. 12" sounds about right though.
And for a Russian I would say that's perfect.

I agree.

The light output of both 5.0 and 10.0 is similar but the UVB output is higher in the latter, I think.

I would go for the 10.0 and use as normal

 

[Tom]

Both bulbs make the same amount of light. The 5.0 makes half the UV of the 10.0. With a UV meter you can see that the 5.0 makes almost no UV. The 10.0 only makes a little UV and the bulb must be mounted no more than 10-12" away for the tortoise to get any UV benefit from it. Using a 5.0 is a pointless waste of money for any species.

The stronger bulbs that emit more UV are the Arcadia 12% HO bulbs. The emit a very high amount of UV and they must be mounted at least 18" or higher above the tortoise, and its only necessary to run them for 3-5 hours a day, mid day. This simulates the UV levels outside in the sun. UVB levels are zero in the morning and late afternoon, even in direct warm sunshine. Later in the morning UV levels quickly rise, peak mid day, and then fall into the afternoon, so says my UVB meter.

When I first got my Solarmeters, I pulled them out of the box at 4:30 pm, took them outside and pointed them right at the sun. I got a reading of zero. I thought they were malfunctioning somehow. I brought them in and put them under my 10.0 bulbs and got a low reading. Okay, I thought, they are working. Next morning I tried them outside again. Zero. How could this be? I tried again later in the morning and got a low reading. By 11am I was getting a pretty high reading. Noon and 1 pm saw ever higher numbers. It started dropping by 2 pm, and by 4pm it was almost zero again. This was in late winter, almost spring. Readings are higher for longer in summer.

The point is, without a meter, you are just guessing. Sort of like not using a thermometer. "Umm…. yeah. It feels kind of warm enough…" NO! Use a thermometer to get your enclosure temperatures set correctly AND use a UVB meter to set your UVB lamps correctly.

I like this meter: https://www.solarmeter.com/model65.html

 

[Tom]

I'm not sure if you can have a problem where a tort gets too much UVB. I'd like to know for sure if that's true or not.

Yes. You absolutely can have too much UV from an improperly mounted, or improperly used indoor artificial UV bulb. Eye damage and the equivalent of "sunburn" can happen, and often does.

Outdoors, the danger would be more from over heating than too much UV, but many tortoises avoid the mid day sun and hide out in the shade. Mine don't do this on cooler winter days, they stay in the sun all day, so it makes me think they are avoiding the mid day heat, not the mid day high UV levels. On the other hand, if it were warmer, would they still do this? Are they taking in excess UV on these cooler days, in exchange for staying warmer? Also, UV levels are much lower in winter, so this complicates our assumptions and speculations as well...

 

[Sara G.]

Thank you for the explanation Tom! you're always there to help full in my mental blanks.
I learn something new every day on this site for sure.

 

[Linhdan Nguyen]

Both bulbs make the same amount of light. The 5.0 makes half the UV of the 10.0. With a UV meter you can see that the 5.0 makes almost no UV. The 10.0 only makes a little UV and the bulb must be mounted no more than 10-12" away for the tortoise to get any UV benefit from it. Using a 5.0 is a pointless waste of money for any species.

The stronger bulbs that emit more UV are the Arcadia 12% HO bulbs. The emit a very high amount of UV and they must be mounted at least 18" or higher above the tortoise, and its only necessary to run them for 3-5 hours a day, mid day. This simulates the UV levels outside in the sun. UVB levels are zero in the morning and late afternoon, even in direct warm sunshine. Later in the morning UV levels quickly rise, peak mid day, and then fall into the afternoon, so says my UVB meter.

When I first got my Solarmeters, I pulled them out of the box at 4:30 pm, took them outside and pointed them right at the sun. I got a reading of zero. I thought they were malfunctioning somehow. I brought them in and put them under my 10.0 bulbs and got a low reading. Okay, I thought, they are working. Next morning I tried them outside again. Zero. How could this be? I tried again later in the morning and got a low reading. By 11am I was getting a pretty high reading. Noon and 1 pm saw ever higher numbers. It started dropping by 2 pm, and by 4pm it was almost zero again. This was in late winter, almost spring. Readings are higher for longer in summer.

The point is, without a meter, you are just guessing. Sort of like not using a thermometer. "Umm…. yeah. It feels kind of warm enough…" NO! Use a thermometer to get your enclosure temperatures set correctly AND use a UVB meter to set your UVB lamps correctly.

I like this meter: https://www.solarmeter.com/model65.html

Thank you!
I know doctors say sunlight before 10am and in the evening are healthy because they provide vitamin D but do not give you the risk of skin cancer because something about the rays of the sun. I dont remember exactly. But sun early morning and evening are healthy, do not tan your skin or increase your risk of getting skin cancer. This might be linked to why theres no uvb readings on the meter?
Could overexposure of uvb in tortoises be similar to humans being overexposed to the sun and getting skin cancer? It kind of sounds like overexposure to uvb from the sun is unhealthy for us too. Though too much of anything is unhealthy.

 

[Tom]

Could overexposure of uvb in tortoises be similar to humans being overexposed to the sun and getting skin cancer?

I've never heard of a single case of cancer of any kind in any tortoise. Sharks don't get cancer either…

Physical damage in tortoises would be similar the physical damage a person would get with too much UV exposure, although I think a tortoise can handle a lot more than a human.

 

[JoesMum]

I've never heard of a single case of cancer of any kind in any tortoise. Sharks don't get cancer either…

Physical damage in tortoises would be similar the physical damage a person would get with too much UV exposure, although I think a tortoise can handle a lot more than a human.

Torts have very little exposed skin due to their shell and scales. I think the cancer risk from over exposure would be minimal.

 

[Linhdan Nguyen]

I've never heard of a single case of cancer of any kind in any tortoise. Sharks don't get cancer either…

Physical damage in tortoises would be similar the physical damage a person would get with too much UV exposure, although I think a tortoise can handle a lot more than a human.

I didnt mean tortoises getting cancer, i just know too much uvb exposure negatively affects them just like too much tanning/exposure to sun can negatively affect us (such as skin cancer).