UVB Question

[AustinnKaine]

So this is my first bearded dragon. I have done a lot of research and I know that UBV and Calcium is very important when it comes to their health.

My concern is that, of course too much of anything can be harmful. My beardie eats 3x daily. He was solely on crickets for the first few days I had him simply because he was taking well to the cucumbers. (I cut them small enough so he can easily swallow, smaller than space between eyes) He is currently eating about 80% crickets, 20% cucumber.

I will attach some photos of the setup, as well as the specifics on the light.
If he is too close to the light please let me know. I've been having a hard time setting up the enclosure so he can get close enough to the basking spot because my terrarium is so vertically inclinde.

 

[CooperDragon]

That UVB light puts out optimal UVB at around 6-8''. If you set the closest basking area 8'' below the bulb it should be sufficient. You'll also want the temperatures to be between about 100-105 in the basking area with some areas around that in the 90s and a cooler area around 75-80. This will give him a gradient so he can move around and choose what he's exposed to at different times of the day.

I'd limit the amount of cucumber you offer. It has high water content but isn't the best for them nutritionally. The 80% bugs is good so keep that up. I like to reference this list when I try to find good items to offer in a salad: http://www.beautifuldragons.com/Nutrition.html

 

[AustinnKaine]

Okay thanks for the salad tip. My main concern is that there is too much UVB being made available. The wood piece that i bought, (not the one i built) Has about an 8" Spot from the uvb. The perch I built for him to mainly bask in at around 105-107 degrees also puts him within about 4" of the uvb light.

The uvb puts out 50 uvb which is 100 microwatts @ about 4".

Is this too much for Raji ?

 

[AustinnKaine]

He also holds his head as high as possible as if he is trying to get even closer?

 

[CooperDragon]

Close proximity can produce dangerous UVB output so I wouldn't allow him to get closer than about 6'' without testing the output with a UV Meter. Is that how you're getting the 100uW reading? That level should be OK but I would double check that reading first.

 

[AustinnKaine]

Close proximity can produce dangerous UVB output so I wouldn't allow him to get closer than about 6'' without testing the output with a UV Meter. Is that how you're getting the 100uW reading? That level should be OK but I would double check that reading first.

It came on the box label. It gave uW output for defined distances.

 

[CooperDragon]

I wouldn't trust those completely. It's best to double check with a UV Meter. If you don't have one then I'd stick with 6-8''. That's based on testing I've done with that bulb. Optimal basking range is about 3-5 UVI or so.

 

[HKzForDayz]

Never take the word of manufacturers as truth. Look at all the untruths the pet industry peddles about bearded dragon care.

 

[CooperDragon]

I just measured my Desert 50 (in a reflective Zilla Slimline fixture) and recorded 9.1 UVI in the center of the bulb. This is a very high reading and could be harmful. At 6'' I read 5.1 and at 8'' I read 3.4. You can see the output drops off quickly so these lights aren't very effective at much distance (which is why I recommend T5 bulbs for larger tanks), but the 6-8'' range produces an output comparable to mid morning and late afternoon UVB levels which is much safer to provide for extended periods of time.

 

[AustinnKaine]

My UVB shines through a pretty fine grated screen, would that effect it enough to warrant a 4" distance as opposed to 6-8?

He has the option to be a little further away if he would like. I can take a picture if that helps.

 

[CooperDragon]

The screen will cut the UVB a bit, yes. I re-tested using the mesh top from my Exo Terra tank which is similar to a window screen. At 4'' I read 4.8 which is OK. Be careful though because at 3'' I measured 7.2 which is a bit high. Based on this, with the screen you may be OK at 4'' but I wouldn't go closer. Keep in mind that at that close range the light may appear visually quite intense so keep a lookout for signs of eye irritation such as eyes closed often while basking.

 

[AustinnKaine]

The screen will cut the UVB a bit, yes. I re-tested using the mesh top from my Exo Terra tank which is similar to a window screen. At 4'' I read 4.8 which is OK. Be careful though because at 3'' I measured 7.2 which is a bit high. Based on this, with the screen you may be OK at 4'' but I wouldn't go closer. Keep in mind that at that close range the light may appear visually quite intense so keep a lookout for signs of eye irritation such as eyes closed often while basking.

Thanks for your help and patience.

 

[kingofnobbys]

I wouldn't trust those completely. It's best to double check with a UV Meter. If you don't have one then I'd stick with 6-8''. That's based on testing I've done with that bulb. Optimal basking range is about 3-5 UVI or so.

UVI = 3 - 5 is barely adequate for a central bearded dragon IMO, in their native range in tropica; central Australia's dry sevannahs and deserts here, even now at the end of summer, UVI will be 11 - 13
(see http://www.bom.gov.au/australia/charts/UV.shtml) .

annual av UVI

September av UVI

December av UVI

Breeding season here for bearded dragons is from September - January.

Need to bask for a full day under fake sunlight (UVA and UVB from a MVB, CFB , T5 or T8) to get the same dose of UVA and UVB as they can (HERE) if they get 30 - 45 mins in the mid morning or mid afternoon direct sunlight).
Hardly anywhere in Australia will have a UVI as low as 5 in spring thro late autumn. Certainly no where that bearded dragons are found living in the wild.

 

[Taterbug]

OP - I'd stick with 6" as the closest and not worry overly about perfecting the lighting in this setup. What are the dimensions? It looks like you'll be due for larger enclosure in not too long.

For most captive situations UVI of 3-5 will be fine, and is actually quite a bit higher than the "standard" setups. This recommendation by researchers and leading experts in UV provision for captive species. It is based in field observation and species habits as well as providing safe husbandry. I'm not sure if your suggesting a UVI of 11-13 but for most captive situations this is not appropriate for the vast majority of captive habitats.

The weather bureau reports you shared are midday UV indices. Indices follow a similar pattern as heat peaking at mid day (when reptiles are much less active). Unfortunately I don't have historical charts at the moment to compare summer values but these charts help illustrate the trend.

Wild dragons, while they may shuttle in and out of the sun all day, do the majority of their basking in the morning and evening and retreat for the parts of the day where the sun is so baking. I'd need to double check but one paper found that dragons did most of their basking prior to 10 or 11 am.

For the most part captive reptiles don't have half the options that wild ones do for photo-regulation. Also, many owners expect their lizards to be basking for most of the day, so offering lower levels over longer periods is often a safe choice. When offering higher levels (3-5) is best done with opportunities for the lizard to choose both heat and UV exposures.

While UVA and the visible spectrum of lamps are very unlike the sun, as far as UVB goes 30 mins under a good lamp giving a UVI of 3 will yield much the same effect as 30 mins under the sun when the UVI is 3 (as measured with a solar meter)

 

[Drache613]

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