UVI Intensity & Duration

[ATHiker17]

We have a Hermann's tortoise that is estimated to be 6 weeks old. We're running an Arcadia 12% at 14.5 inches just over the basking area and it's slightly filtered by a 1/2" welded wire screen. As measured by a Solarmeter 6.5R, the UVI is 8.5 when taken 4 1/2" above the basking zone. Based on the inverse square law, my uvi should be 4.0 at the basking zone and ~4.5 to 4.8 at the top of his shell.

Given that those numbers are near the top of Ferguson zone 3, should I cut back on the recommended 12 hours of daily uvb? I was thinking something closer to 6 hours... What do the experts think?

The first photo shows the daytime setup and the second photo shows everything closed up at night for added humidity.

 

[The_Four_Toed_Edward]

@Alex and the Redfoot can probably answer your question more specifically, but basically the 12 hours isn't the recommendation anymore, but instead few hours per day is recommended, so somewhere around 2-4 hours of UVB per day.

 

[Alex and the Redfoot]

We have a Hermann's tortoise that is estimated to be 6 weeks old. We're running an Arcadia 12% at 14.5 inches just over the basking area and it's slightly filtered by a 1/2" welded wire screen. As measured by a Solarmeter 6.5R, the UVI is 8.5 when taken 4 1/2" above the basking zone. Based on the inverse square law, my uvi should be 4.0 at the basking zone and ~4.5 to 4.8 at the top of his shell.

Given that those numbers are near the top of Ferguson zone 3, should I cut back on the recommended 12 hours of daily uvb? I was thinking something closer to 6 hours... What do the experts think?

The first photo shows the daytime setup and the second photo shows everything closed up at night for added humidity.

Hello!
Yes, keeping the UVB light on around 4-6 hours a day is more natural (given sufficient UVI, of course).

A typical distance to basking area for Arcadia Desert lamps is 18-20". Meshed top definitely attenuates lamp's output but I would still do a few more control measurements (probably, a heat lamp dome "shadows" UV light coming from the tube). I would also move the UVB fixture a bit closer to the middle of the enclosure to provide better UV coverage.

You can also consider to keep the enclosure cover during the day: higher humidity helps to mitigate desiccating effect from a basking lamp.

 

[ATHiker17]

Hello!
Yes, keeping the UVB light on around 4-6 hours a day is more natural (given sufficient UVI, of course).

A typical distance to basking area for Arcadia Desert lamps is 18-20". Meshed top definitely attenuates lamp's output but I would still do a few more control measurements (probably, a heat lamp dome "shadows" UV light coming from the tube). I would also move the UVB fixture a bit closer to the middle of the enclosure to provide better UV coverage.

You can also consider to keep the enclosure cover during the day: higher humidity helps to mitigate desiccating effect from a basking lamp.

Thanks for the input! I have a humidifier running adjacent to the open top and during the day my humidity gradient slopes up from 58% near the basking area to 75% at the cool end. At night, after putting the cover in place, the humidity of the entire enclosure quickly climbs to 82-85%.

He gets a 30 minute lukewarm soak every morning and he's sprayed with a mister 3-4 times a day. Out of curiosity I've weighed him post morning soak and again in the evening just before closing things up a few times. The scale weighs to within 1/100 of a gram and there hasn't been any appreciable weight loss from a day of basking.

 

[Alex and the Redfoot]

Thanks for the input! I have a humidifier running adjacent to the open top and during the day my humidity gradient slopes up from 58% near the basking area to 75% at the cool end. At night, after putting the cover in place, the humidity of the entire enclosure quickly climbs to 82-85%.

He gets a 30 minute lukewarm soak every morning and he's sprayed with a mister 3-4 times a day. Out of curiosity I've weighed him post morning soak and again in the evening just before closing things up a few times. The scale weighs to within 1/100 of a gram and there hasn't been any appreciable weight loss from a day of basking.

Sounds good!
With such high-precision scales, can you also weigh your tortoise before and after soaking? I'm curious about water intake during soaks.

The trouble with heat lamps is not that they dehydrate tortoise, but dry out growing keratin. There will be no noticeable weight loss, but some extent of so-called "pyramiding". Lamps with wide beam, good output gradient and moderate IR-A seem to work best (so non-halogen incandescent flood lights only).

 

[Littleredfootbigredheart]

Thanks for the input! I have a humidifier running adjacent to the open top and during the day my humidity gradient slopes up from 58% near the basking area to 75% at the cool end. At night, after putting the cover in place, the humidity of the entire enclosure quickly climbs to 82-85%.

He gets a 30 minute lukewarm soak every morning and he's sprayed with a mister 3-4 times a day. Out of curiosity I've weighed him post morning soak and again in the evening just before closing things up a few times. The scale weighs to within 1/100 of a gram and there hasn't been any appreciable weight loss from a day of basking.

Hello! You actually want to avoid using a humidifier, they can be really problematic and only temporarily boost your levels instead of maintaining your ambient humidity properly, the safest most efficient way is a proper closed chamber set up with a thick damp substrate layer, unfortunately these wooden houses really aren’t the best starter choice.

I’m going to leave some links that will hopefully help you out

This thread covers correct equipment(uvb, heating bulbs, lighting etc), correct levels, importance of a closed chamber for younger tortoises(only way to maintain the humidity you need), appropriately maintaining the humidity, safe substrates, there’s lots of visual examples for everything, and a really handy diet link to check out! If going with a greenhouse, the lower the ceiling height, whilst still allowing for recommended bulb height, the better! But I’ll add some more ideas below for closed chambers

Housing young Russian/Herman

Hello there! In this thread, I’m going to include some information on an effective way to tackle a starter set up/a way you can build a bigger size once your baby is an adult. I know it looks a lot to go over, I like to make sure all bases are covered, I’m happy to break down any information...

tortoiseforum.org

This includes different closed chamber options, some do definitely work better than others

Visual inspiration

Hi guys! I’ve had some lovely messages complimenting me on my care sheets I made for all the visuals they include! That makes me so happy because as a visual learner myself, that was my goal🥰 I’ve recently had some requests for some more visual inspiration for set ups that can house babies/...

tortoiseforum.org

Perhaps this idea in particular might be of use to you


Lastly, this one here is good to go over and keep on hand, it’ll help you avoid the wrong bulbs, substrates, housing etc, I always encourage double checking purchases on the forum too before buying

Common keeping errors

Hello everyone! I’d been a long time lurker on this site long before joining just under a year ago now, over that time I’ve seen these husbandry issues come up time and time again, sometimes with dire consequences☹️ I thought this thread might serve as a good visual guide for these common...

tortoiseforum.org

Hope they come in useful! Welcome to the forum

 

[ATHiker17]

Hello! You actually want to avoid using a humidifier, they can be really problematic and only temporarily boost your levels instead of maintaining your ambient humidity properly, the safest most efficient way is a proper closed chamber set up with a thick damp substrate layer, unfortunately these wooden houses really aren’t the best starter choice.

I’m going to leave some links that will hopefully help you out

This thread covers correct equipment(uvb, heating bulbs, lighting etc), correct levels, importance of a closed chamber for younger tortoises(only way to maintain the humidity you need), appropriately maintaining the humidity, safe substrates, there’s lots of visual examples for everything, and a really handy diet link to check out! If going with a greenhouse, the lower the ceiling height, whilst still allowing for recommended bulb height, the better! But I’ll add some more ideas below for closed chambers

Housing young Russian/Herman

Hello there! In this thread, I’m going to include some information on an effective way to tackle a starter set up/a way you can build a bigger size once your baby is an adult. I know it looks a lot to go over, I like to make sure all bases are covered, I’m happy to break down any information...

tortoiseforum.org

This includes different closed chamber options, some do definitely work better than others

Visual inspiration

Hi guys! I’ve had some lovely messages complimenting me on my care sheets I made for all the visuals they include! That makes me so happy because as a visual learner myself, that was my goal🥰 I’ve recently had some requests for some more visual inspiration for set ups that can house babies/...

tortoiseforum.org

Perhaps this idea in particular might be of use to you
View attachment 396789

Lastly, this one here is good to go over and keep on hand, it’ll help you avoid the wrong bulbs, substrates, housing etc, I always encourage double checking purchases on the forum too before buying

Common keeping errors

Hello everyone! I’d been a long time lurker on this site long before joining just under a year ago now, over that time I’ve seen these husbandry issues come up time and time again, sometimes with dire consequences☹️ I thought this thread might serve as a good visual guide for these common...

tortoiseforum.org

Hope they come in useful! Welcome to the forum

Thank you for this information. I'll definitely be tweaking things in the coming days.