Lighting Discussion

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Lighting Discussion

Postby kingofnobbys » Fri Jul 19, 2019 12:55 am

Was wondering when they'd put up their revised UV guidelines when they introduced the new 14% UVB T5ho tubes.

https://www.arcadiareptile.com/lighting ... n-baskers/ ties in very nicely with their old version for pogona vitticeps ie
Image
which happens to give UVB flux.
Which indicated the appropriate distance from their 12% UVB T5ho tube was 30cm (as well) based on the tech specs for their 12%UVB T5ho tubes summarized succinctly in an easy to read graphical form by me and shown below for their tubes in a good reflector hood
Image
and this is how to use the charts :
Image
Last edited by kingofnobbys on Sat Jul 20, 2019 10:15 pm, edited 1 time in total.
CBDs: Cleopatra & Caesar born 28Jan19.
Puff (RIP 10Dec15),Rex (RIP 16Mar17),Toothless (RIP 26Nov17).Peppa (RIP 22Mar19).
EBTSs : George & Mildred (born july 2010).
EWSs : new rescues Gutzy (F) 27Sep19, juvenile Cheakie (M) 21Oct19
Fluffy (F) rescued injured by lawnwacker 14Nov17, Wriggles (F) - injured rescue, over 8 yrs old, RIP 2Feb16 old age. Lucky juvenile (M) - cat attack rescue (lost r-eye, broken r-lower jaw), fatal SI RIP 21Jul2010.
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Lighting Discussion

Postby CooperDragon » Fri Jul 19, 2019 7:55 am

Moved by moderator from enclosures to advanced lighting/enclosures
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Re: Lighting Discussion

Postby claudiusx » Fri Jul 19, 2019 8:08 am

Arcadias new lighting guidelines:

[Click image to enlarge]


They do not base their recommendations anymore on mW uv, but instead on UVI, as is becoming the norm with almost all other companies.

Additionally, the updated chart differs from the old chart in one main aspect, providing 0 UVI at a point in the enclosure. Which wasn't a suggestion in the first chart.

All in all, I like their new recommendations much better. Basking UVI is higher than I typically would like, but it's acceptable because they are stressing the importance of a gradient down to 0, which is something that hasn't been stressed enough here.

Which indicated the appropriate distance from their 12% UVB T5ho tube was 30cm

The updated recommendation is 30-45cm for the 12%, as shown in their chart. I'm sure it's because they realized that in some tanks 30cm won't allow a gradient down to 0 UVI in the cool zone.

-Brandon
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P.S. We have lots of pictures ;)
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Re: Lighting Discussion

Postby kingofnobbys » Fri Jul 19, 2019 8:23 am

The dragon can if it has access to a hide , seek out ZERO UV by simply going into it's hide.

So maybe since all keepers ( I'm yet to come across one who doesn't ) provide a hide for their dragon usually in either the warm zone ( doubles as a basking spot on top of it) or the cool zone, and some of use provide two hides ( one in the warm zone the other in the cool zone ), then the dragon , even using the "old" guidelines has easy access to zero UV (in any way you care to monitor it).
Plus they never recommended have the UV linear source covering the ENTIRE length of the viv. So another source of very low or zero UV .

I'd be careful about putting words that are not their own into their mouths or in assuming they are following suit with what other light manufactures are doing.
Arcadia still provide UVA & UVB flux data and specifications on their UV products , they are doing this for sound scientific reasons.
CBDs: Cleopatra & Caesar born 28Jan19.
Puff (RIP 10Dec15),Rex (RIP 16Mar17),Toothless (RIP 26Nov17).Peppa (RIP 22Mar19).
EBTSs : George & Mildred (born july 2010).
EWSs : new rescues Gutzy (F) 27Sep19, juvenile Cheakie (M) 21Oct19
Fluffy (F) rescued injured by lawnwacker 14Nov17, Wriggles (F) - injured rescue, over 8 yrs old, RIP 2Feb16 old age. Lucky juvenile (M) - cat attack rescue (lost r-eye, broken r-lower jaw), fatal SI RIP 21Jul2010.
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Re: Lighting Discussion

Postby claudiusx » Fri Jul 19, 2019 8:34 am

They provide it, but it's not what they are using for recommendations for their users.

kingofnobbys wrote:So maybe since all keepers ( I'm yet to come across one who doesn't ) provide a hide for their dragon usually in either the warm zone ( doubles as a basking spot on top of it) and some of use provide two hides ( one in the warm zone the other in the cool zone )

*raises hand* I don't provide hides. I know a lot of people who don't provide hides.

kingofnobbys wrote: even using the "old" guidelines has easy access to zero UV (in any way you care to monitor it).

Not necessarily. Don't take this personal, but one of my issues with telling people to aim for a certain level at the basking spot, is usually you're not taking into account the whole picture. If they have a bulb that spans 3/4 the tank, and their basking surface is only 10cm off the floor, or it's simply just a brick on the bottom of the tank, there is no where in that tank that is going to have 0 UVI. The bulb will be too close because the basking surface is too close to the floor. I would hazard a guess that this is why Arcadia provided an acceptable range for their bulbs. So for the example I gave, the person knows they can simply raise the bulb a bit higher, since they have a low basking surface. That way the basking surface has acceptable uvi, and the cool side gradient doesn't get too high.

Either way, there isn't anything wrong with a uv gradient down to 0 IMO. I don't know why anyone would disagree. A gradient is about the best thing we can provide, that way they can chose where they want to be. I would imagine you agree on this point. If not, well I suppose their is no point discussing it.

Either way, Arcadia changed their recommendations for a reason. They added a gradient to 0 for a reason, and they switched to UVI for a reason. It's all I've been trying to advise here. We can guess as to why they did it, or we can send them an e mail and ask. I won't be doing that but If you do i'm sure it would be good information to share.

kingofnobbys wrote:Arcadia still provide UVA & UVB flux data and specifications on their UV products , they are doing this for sound scientific reasons.


I don't believe they do, at least not on their site anymore.
If you click on their florescent bulb products, they all mention UVI levels, not uv flux.
Once again, it's because it's whats considered the standard in regards to d3 synthesis measuring. I'm sure flux is the standard in other areas of light measurement as you've already demonstrated in other threads. But, I think it's pretty telling when everyone who's anyone in the herp lighting world has been using UVI lately.

-Brandon
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P.S. We have lots of pictures ;)
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Re: Lighting Discussion

Postby kingofnobbys » Fri Jul 19, 2019 5:51 pm

Considering I buy my lights in bulk , and this applied to my latest Arcadia purchase of T5 12%UVB tubes ( 4 off ) and I'm yet to change my first set that came with my SlimLine reflector hoods (I've actually got 8 spare Arcadia T5ho 12%UVB 24W tubes on hand for two bearded dragons + 4 slimline kits & 4 spare tubes), it's gonna be a good while before I need to look at buying more + the fact no local pet shop actually stocks Arcadia anything here in my town ( so I can't just visit a pet shop and take a squiz at the packaging and documentation in the box ).

So we'll just have to wait for someone else to have enough interest to come along and confirm your assertion on buying a new tube sometime in the near future ---- not holding my breath on that happening as this thread will likely be buried and forgotten by then.
It's the tech data that comes with each tube or mvb that's important , company web sites don't always reflect the full scope of the specs and useage guidelines provided with their products. To include everything makes for a very detailed by confusing webpage and those who set up the webpages are usually not the engineers but marketing / sales people who have a "different" focus.

I'll continue advising about 200 microW UVB flux / sq.cm at the basking spot and cool zone about 1/3 that with the tube no more than 2/3 the length of the viv.
As these levels are fine and I'm yet to see proof that lower levels (in UVB and UVA flux or in UV-Index if one insists on using UV-Index as the "measure") are appropriate for pogona species.
CBDs: Cleopatra & Caesar born 28Jan19.
Puff (RIP 10Dec15),Rex (RIP 16Mar17),Toothless (RIP 26Nov17).Peppa (RIP 22Mar19).
EBTSs : George & Mildred (born july 2010).
EWSs : new rescues Gutzy (F) 27Sep19, juvenile Cheakie (M) 21Oct19
Fluffy (F) rescued injured by lawnwacker 14Nov17, Wriggles (F) - injured rescue, over 8 yrs old, RIP 2Feb16 old age. Lucky juvenile (M) - cat attack rescue (lost r-eye, broken r-lower jaw), fatal SI RIP 21Jul2010.
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Re: Lighting Discussion

Postby claudiusx » Fri Jul 19, 2019 6:13 pm

kingofnobbys wrote:I'll continue advising about 200 microW UVB flux / sq.cm at the basking spot and cool zone about 1/3 that with the tube no more than 2/3 the length of the viv.
As these levels are fine and I'm yet to see proof that lower levels (in UVB and UVA flux or in UV-Index if one insists on using UV-Index as the "measure") are appropriate for pogona species.


Do not not feel it better to simply suggest a distance instead? Why complicate it for someone who is seeking advice. Either they need an expensive instrument to follow your advice, or they need to look online to find a chart.

Of course you could provide a chart, but why not simply state a distance range (much like Arcadia has done) as opposed to a range immeasurable by the average person seeking advice.
kingofnobbys wrote: company web sites don't always reflect the full scope of the specs and useage guidelines provided with their products. To include everything makes for a very detailed by confusing webpage and those who set up the webpages are usually not the engineers but marketing / sales people who have a "different" focus.

It's actually usually the opposite. The packaging is simplified and the webpage is detailed. And It's not fair to assume that whoever put together Arcadias site didn't know what they were doing. It's a big assumption.

Here is a quote from their lighting article that lends credence to the fact that their guide wasn't just haphazardly put together.

Here at Arcadia Reptile we decided to re-write the lighting advice that was being given. We used science when doing so rather than generalisations. Now, keepers are able to use the published outputs of lamps to re-create the UV levels (UVI) of species in the wild. We studied the wild UVI in the environments of common species and we looked at the habitats of popular species with the aim of understanding how each species used solar energy. We looked at skin thickness in each species and checked this with tetrachromacy (the reptile’s ability to see UV light), aiming to find how much light would be available per species in the wild. We also discovered what is now known as leaf or rock scatter illumination. These are the terms used to describe light that travels down from the forest canopy or passes through holes and gaps in rocks. This means that those species which were traditionally classed as low light requiring species, in fact are now known to use UV levels efficiently.


Either way, I think it's bad form to offer old advice simply because your bulbs you bought awhile ago still say that. The manufacturer changed their recommendation for a reason, and it is only wise to take that into consideration.

Do I think 200 mw at the basking surface is too much? No, not really. But my concern is too much throughout the tank. 150, 200, 250 mW, fine, as long as their is a gradient to get away from. And the higher that basking number goes, the harder it is to achieve that low gradient to 0.

-Brandon

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Re: Lighting Discussion

Postby kingofnobbys » Fri Jul 19, 2019 9:43 pm

claudiusx wrote:
kingofnobbys wrote:I'll continue advising about 200 microW UVB flux / sq.cm at the basking spot and cool zone about 1/3 that with the tube no more than 2/3 the length of the viv.
As these levels are fine and I'm yet to see proof that lower levels (in UVB and UVA flux or in UV-Index if one insists on using UV-Index as the "measure") are appropriate for pogona species.


Do not not feel it better to simply suggest a distance instead? Why complicate it for someone who is seeking advice. Either they need an expensive instrument to follow your advice, or they need to look online to find a chart.

the charts are there (online and easy to find, at manufactures sites ,or on message boards) , so that's no real excuse.

The beauty of having a chart or graph of the "as new" output is that this gives owners the opportunity to monitor the performance of their globes or tubes UVA & UVB performance, and to know exactly when the output has decayed to below say 40% the "as new" performance , I use 40% on UVA and UVB flux at a standardized distance (in my case I choose 12") as my time to downgrade to a species who needs less UV or to toss out and replace.

A rapid drop in UVB with an increase in UVA with a decaying phosphor coating will not be picked up by a UV-Index meter as it's not designed to detect UV in a quantitative way but measures UV across A and B bands In a very qualitative and subjective manner ( [color=#FF0000]modeling approximately the UV response of HUMAN SKIN
).

I invite you to get hold of some more recent scholarly articles on UV - emitting LiCaBO3:Gd3+ phosphor decay , I refer you to wileyonlinelibrary.com/journal/luminescence where there studies of how phosphors decay and how the UV spectra of their excitation emissions over time as the phosphors decay / breakdown that make very interesting reading (even if very technical and scientific and require deep knowledge of materials , chemistry and physics).
This has been a long term interest of mine .

Therefore the user could easily be lulled into a false sense of security thinking their tube is performing fine when in fact the phosphors are decaying and the UV emission spectrum is shifting and changing , and the reptile is no longer receiving sufficient UVB.

I have a UVA and a UVB meter that I use regularly. These instruments are not that expensive and IMO well worth having in hand in your "kit"..
[/color]
Of course you could provide a chart, but why not simply state a distance range (much like Arcadia has done) as opposed to a range immeasurable by the average person seeking advice.
kingofnobbys wrote: company web sites don't always reflect the full scope of the specs and useage guidelines provided with their products. To include everything makes for a very detailed by confusing webpage and those who set up the webpages are usually not the engineers but marketing / sales people who have a "different" focus.

It's actually usually the opposite. The packaging is simplified and the webpage is detailed. And It's not fair to assume that whoever put together Arcadias site didn't know what they were doing. It's a big assumption.

Here is a quote from their lighting article that lends credence to the fact that their guide wasn't just haphazardly put together.

>> I prefer to see the scientific data that was used and make my own assessment , I note they have not cited any scientific papers.
I hold myself to high scientific standards regarding providing citations in correct scientific literature format and don't think it's unreasonable expect the same from the engineers and scientists employed by companies like Zoo Med, Exo Terra and Arcadia Reptile , as indeed was my management's expectations when I was working as a researcher for BHP and my expectation when I became a senior and then a principal engineer, and similarly when I was working at my local university..



Here at Arcadia Reptile we decided to re-write the lighting advice that was being given. We used science when doing so rather than generalisations. Now, keepers are able to use the published outputs of lamps to re-create the UV levels (UVI) of species in the wild. We studied the wild UVI in the environments of common species and we looked at the habitats of popular species with the aim of understanding how each species used solar energy. We looked at skin thickness in each species and checked this with tetrachromacy (the reptile’s ability to see UV light), aiming to find how much light would be available per species in the wild. We also discovered what is now known as leaf or rock scatter illumination. These are the terms used to describe light that travels down from the forest canopy or passes through holes and gaps in rocks. This means that those species which were traditionally classed as low light requiring species, in fact are now known to use UV levels efficiently.


Either way, I think it's bad form to offer old advice simply because your bulbs you bought awhile ago still say that. The manufacturer changed their recommendation for a reason, and it is only wise to take that into consideration.

Do I think 200 mw at the basking surface is too much? No, not really. But my concern is too much throughout the tank. 150, 200, 250 mW, fine, as long as their is a gradient to get away from. And the higher that basking number goes, the harder it is to achieve that low gradient to 0.

>>> so long as the dragon has access to a hide , It has access to zero UV if it needs to seek "shade" , just as having an area not illuminated by the UV source provides very low UV or even zero UV.

…. obsessing about level of uv in the "shady" area is really just muddying the waters IMO.



-Brandon

-Brandon
CBDs: Cleopatra & Caesar born 28Jan19.
Puff (RIP 10Dec15),Rex (RIP 16Mar17),Toothless (RIP 26Nov17).Peppa (RIP 22Mar19).
EBTSs : George & Mildred (born july 2010).
EWSs : new rescues Gutzy (F) 27Sep19, juvenile Cheakie (M) 21Oct19
Fluffy (F) rescued injured by lawnwacker 14Nov17, Wriggles (F) - injured rescue, over 8 yrs old, RIP 2Feb16 old age. Lucky juvenile (M) - cat attack rescue (lost r-eye, broken r-lower jaw), fatal SI RIP 21Jul2010.
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Re: Are we overexposing our dragons to UV?

Postby kingofnobbys » Sat Jul 20, 2019 10:51 pm

And just to make sure this is tied down
Image
CBDs: Cleopatra & Caesar born 28Jan19.
Puff (RIP 10Dec15),Rex (RIP 16Mar17),Toothless (RIP 26Nov17).Peppa (RIP 22Mar19).
EBTSs : George & Mildred (born july 2010).
EWSs : new rescues Gutzy (F) 27Sep19, juvenile Cheakie (M) 21Oct19
Fluffy (F) rescued injured by lawnwacker 14Nov17, Wriggles (F) - injured rescue, over 8 yrs old, RIP 2Feb16 old age. Lucky juvenile (M) - cat attack rescue (lost r-eye, broken r-lower jaw), fatal SI RIP 21Jul2010.
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