Natural sunlight vs MVB or uvb bulbs

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Natural sunlight vs MVB or uvb bulbs

Postby KevinsMom33 » Wed Nov 13, 2019 9:14 am

More than anything I am curious about the ratio of natural sunlight vs artificial light - either by mercury vapor bulbs or UVB bulbs.
Does anyone actually know what the equivalent is - as in 10 hours with MVB is equal to 2 hours in natural sunlight.
I've always been curious about that, and I can't really find that info anywhere.
My dragons in the summer spend most sunny days playing and sunning themselves outside and in natural sun but in the winter in Connecticut, they are stuck indoors - I always out in new fresh bulbs before we go in for the winter.
Anyone??
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Re: Natural sunlight vs MVB or uvb bulbs

Postby MrSpectrum » Wed Nov 13, 2019 9:23 am

Bulbs are going to vary in... potency, for lack of correct term, but with a bulb (unlike the sun) it's more a matter of distance. Checking threads on UVB here would direct you to articles on how much is good/bad, and if you want, UVB meters are available on Amazon that can tell you the strength (and also confirm if/when your bulb needs replacing).

See: How Long Should Beardies Be Under UVB?
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Re: Natural sunlight vs MVB or uvb bulbs

Postby claudiusx » Wed Nov 13, 2019 9:31 am

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Re: Natural sunlight vs MVB or uvb bulbs

Postby claudiusx » Wed Nov 13, 2019 9:35 am

Hi there,

I'm at work right now so I'll give a more detailed answer when I get home tonight - but essentially you're after uva exposure and uvb exposure. Uva is a bit more unknown as to how much they should really be exposed to, but for uvb most professionals use the UVI scale.
The solarmeter 6.5 measures UVI so if you had one, youd be able to know what level the sun was giving you at your part of the world at whatever time of the day.

Aside from that, natural sunlight is great for them. In winter time I'd just stick with uvb bulbs we know to work well, at distances we know work well.

Will get more detailed later ;)

-Brandon
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Re: Natural sunlight vs MVB or uvb bulbs

Postby MrSpectrum » Thu Nov 14, 2019 10:49 am

claudiusx wrote:The solarmeter 6.5 measures UVI so if you had one, youd be able to know what level the sun was giving you at your part of the world at whatever time of the day.

Maybe I'm misunderstanding you. I would think the number to use as a benchmark wouldn't be at one's part of the world, but Central Australia.

FWIW, in the US, the National Weather Service tracks & forecasts UVI daily. Just go to https://www.weather.gov/rah/uv and follow the links for your location, zip, or closest major city.

Also, word has it that the 6.5 and 6.5R are exactly the same meter, but they charge ~$10 more (compare on Amazon) for the little picture of the lizard.
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Re: Natural sunlight vs MVB or uvb bulbs

Postby claudiusx » Thu Nov 14, 2019 11:00 am

MrSpectrum wrote:Maybe I'm misunderstanding you. I would think the number to use as a benchmark wouldn't be at one's part of the world, but Central Australia.

I wasn't saying to use the number you get outside your house as the benchmark, I was saying if you have the meter you would know what level you are getting, which can be used as a comparison to the recommended UVI levels. You can't know what your dragon is being exposed to if you're relying on outside sunlight unless you can measure it. Unlike how most owners CAN rely on the UV exposure their dragons are getting when following distance guidelines for common bulbs. That's all I was stating with that suggestion.

MrSpectrum wrote:FWIW, in the US, the National Weather Service tracks & forecasts UVI daily. Just go to https://www.weather.gov/rah/uv and follow the links for your location, zip, or closest major city.

This is ok, but is not very accurate at all. At least not in my location. Climate never = microclimate. For instance, following the link, the website tells me my area is a very generic 3 right now, however I just went outside and checked, and we are neary a 5 right now. it looks more so like it's just a guess, and not an actual measurement (or at least not an accurate one) which would make sense, as most people don't really care about it lol.

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Re: Natural sunlight vs MVB or uvb bulbs

Postby claudiusx » Thu Nov 14, 2019 11:14 am

KevinsMom33 wrote:More than anything I am curious about the ratio of natural sunlight vs artificial light - either by mercury vapor bulbs or UVB bulbs.

There is no real good comparison here. Like mentioned, you'd need to know the UVI level of your specific area, at the specific times of day that your dragon is outside. And for that you will need either the solarmeter 6.5 or the solarmeter 6.2.
Now personally, I don't like the 6.2 for indoor lamp use, but it is effective outdoors because we know the intensity of the sun, and we know how to calculate a UVI level from the mW uv cm2 that the 6.2 reads. But, for ease of use and simplicity, I'd go with the 6.5 as it directly measures UVI. Here is a link if you're curious on UVI vs. mW UV
viewtopic.php?f=87&t=250316

Anyways, as you can see, you can't really compare. In the tanks if you follow the guidelines most agree on, they have the ability to expose themselves at their basking site to a UVI level of around 3-5~. Your area in the world, or your specific microclimate might never reach UVI levels that high. You might have days where the UVI level never goes over 2.

Simply put, we have a good understanding of the wavelengths of the UV spectrum that produce vit d3 in humans. And it's a safe (or at least the best we have at the time) assumption to think that these wavelengths are also the wavelengths that are needed in other creatures, dragons included.
What isn't known for sure is if there are other parts at play. Other things that the sun provides that increase this d3 synthesis.
I think most would agree that natural sunlight is best if possible, but also don't be fooled into thinking that your natural sunlight is enough, or good enough to fully mimic their natural environment or to meet their needs.

That being said, I think if weather permits, it's always a good idea to let them get some natural sunlight. Even if the UVI level isn't exactly where you want it. Sunlight provides much more benefit than just UVB exposure. But, making sure they also have what they need in their tank, gives extra peace of mind knowing that they won't be lacking anything.

So I'm sorry if this wasn't exactly the answer you were looking for. The reason you haven't' been able to find an answer is because one doesn't exist really.
Truth be told, we don't even know how much time wild dragons spend basking in their natural habitats. Not one study has been done that scientifically answered that question. Only anecdotal "watching" of dragons in nature has been done, as far as i'm aware. Of course it's because meters and trackers would have to be attached to wild dragons, that way we could monitor what level they were exposing themselves to, and for how long. That truly would be an eye opening experiment for everyone. And hopefully it's one that will get done soon.

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Re: Natural sunlight vs MVB or uvb bulbs

Postby MrSpectrum » Thu Nov 14, 2019 11:47 am

claudiusx wrote:
MrSpectrum wrote:Maybe I'm misunderstanding you. I would think the number to use as a benchmark wouldn't be at one's part of the world, but Central Australia.

I wasn't saying to use the number you get outside your house as the benchmark, I was saying if you have the meter you would know what level you are getting, which can be used as a comparison to the recommended UVI levels.

Ha ha. Then I did misunderstand, however unlike the left coast, we're still under nearly a foot of snow. I don't see what value the outside value would be in parts of the world where we have weather too cold for a BD 8 months of the year, and overcast days (I know there's still UV on overcast days) 2nd only to Seattle. All that matters here is how much we can get artificially, aside from some of those 4 months when it is warm enough to take the leetle feller out for some fresh air & sunshine (in one of those portable outdoor enclosures--we got lots of raptors here).

I figure if the meter says my bulb i still good, I might only have to replace it every 7-9 months (if I'm lucky) which will hopefully save enough over his (and other future zards) lifespans to make it worthwhile. YMMV
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Re: Natural sunlight vs MVB or uvb bulbs

Postby KevinsMom33 » Thu Nov 14, 2019 12:36 pm

claudiusx wrote:
KevinsMom33 wrote:More than anything I am curious about the ratio of natural sunlight vs artificial light - either by mercury vapor bulbs or UVB bulbs.


So I'm sorry if this wasn't exactly the answer you were looking for. The reason you haven't' been able to find an answer is because one doesn't exist really.
Truth be told, we don't even know how much time wild dragons spend basking in their natural habitats. Not one study has been done that scientifically answered that question. Only anecdotal "watching" of dragons in nature has been done, as far as i'm aware. Of course it's because meters and trackers would have to be attached to wild dragons, that way we could monitor what level they were exposing themselves to, and for how long. That truly would be an eye opening experiment for everyone. And hopefully it's one that will get done soon.

-Brandon



Hi Brandon - thanks for you information, you seem to know a lot about the subject - So I assume there is no ratio like 1 hour of natural sunshine is the same as 6 hours under a MVB correct?
I'm curious because I live on the East Coast - Connecticut to be exact - and summers are medium to hot average temp is about 85f - but only lasts from only from end of May through early September - so I like to have my kids out in the natural light for as long as possible every (morning coffee on the patio for an hour with mom, since I need vitamin D too -Kevin has free range to go in and out onto the fenced in sunny balcony - never by himself, only when I'm out there too - but he can come and go as he pleases - Nona is always with me, she is much smaller thank Kevin - yes Kevin has deformed/twisted front hands from mbd, walks on his wrists - which is how I got him from the rescue - does NOT stop him). They both get at least 2-3 hours a day of sunshine in the summer months (in the garden area when Kevin's had enough sun, he has a favorite plant that he tucks under in the partial shade) plus inside they have their regular lighting system inside. But in the winter, we are stuck inside - too chilly.

I shouldn't be stunned that no one has ever done any real research on their natural habits - we just take creatures from the wild and assume we, the smart humans, will know how to replicate mother nature. When in actuality, even though I love my dragons - nothing beats nature.
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Re: Natural sunlight vs MVB or uvb bulbs

Postby MrSpectrum » Thu Nov 14, 2019 2:44 pm

KevinsMom33 wrote:I shouldn't be stunned that no one has ever done any real research on their natural habits

I'm not sure that's entirely accurate. Here's a link that could get one started to find any if they exist: Pogona vitticeps
Plug in whatever additional keywords you like after the species name. I've found quite a bit of good info--including studies--that I never knew was out there.

I'm having trouble locating it now (because I can't recall the name), but there's a YT channel owned by an Australian veterinarian who specializes in BDs.
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Re: Natural sunlight vs MVB or uvb bulbs

Postby MrSpectrum » Mon Nov 18, 2019 12:16 pm

MrSpectrum wrote:
KevinsMom33 wrote:I shouldn't be stunned that no one has ever done any real research on their natural habits

I'm not sure that's entirely accurate.

Since I last posted, I came across mention of a study that may (or may not) contain what you're looking for. In Reptiles Magazine, I found this:
How Much UVB Does My Reptile Need?

Ideally, we should be relying upon individual studies made in the wild for every species we keep. Until very recently, no practical methods even existed for measuring UV in the microhabitat of wild reptiles. However, in 2010, a team of herpetologists from Texas Christian University, led by Professor Gary Ferguson, published recordings of daily UV exposure of 15 species of reptiles tracked in the wild, using the UV Index (UVI), measured with a Solarmeter 6.5 UV Index meter. This meter is especially useful, as it measures UV irradiance in the wavelengths that enable vitamin D3 synthesis.

The team noticed that the 15 species could easily be allocated into one of four microhabitats or “zones” (which have since been called the Ferguson Zones) according to their daily sun exposure. The team also suggested that zone allocation could be extended much further. Knowledge of the basking/daylight exposure habits of any species might enable a reasonable estimation of likely UV exposures to be made.

The four Zones may be summarized in this way:
Zone 1 = crepuscular or shade dweller, thermal conformer/
Average exposure: UVI 0-0.7; maximum recorded: UVI 0.6-1.4
Zone 2 = partial sun/occasional basker, thermoregulator
Average exposure: UVI 0.7-1.0; maximum recorded: UVI 1.1-3.0
Zone 3 = open or partial sun basker, thermoregulator
Average exposure: UVI 1.0-2.6; maximum recorded: UVI 2.9-7.4
Zone 4 = mid-day sun basker, thermoregulator
Average exposure: UVI 2.6-3.5; maximum recorded: UVI 4.5-9.5

The average (of all the UVI readings for the microhabitats at the time and place the reptiles were found) might be seen as a suitable “mid-background” level of UVB for the species in each zone. The maximum figures might reflect “one-off” exposures — a single reptile found out in mid-day sun — but they give a rough idea of the maximum levels this type of animal might encounter naturally. This suggests an upper acceptable limit for the UVB gradient to be provided in captivity. A gradient is vital; there must be a full range of UV levels from zero (full shade) to the maximum suggested by the Zone assessment (at the closest point possible between the reptile and the lamp).


It may not be exactly what you're looking for, but it may help, and I thought it quite worthwhile a perusal (what I could understand of it). YMMV.

According to chart in the article, BDs fall between Ferguson Zones 3 & 4, indicating a max. UVI range of 2.9 to 7.4 at the basking site/zone. Seems like quite a range.

I'm trying, but still after several months, I admittedly have some trouble making sense out of this stuff. I found a temporary fix until I can get a proper UVB bulb, and my Solarmeter 6.5 is telling me I have a 1.3 to 1.4 UVI at Zardoz' basking spot. According to the article, I think it's supposed to be higher. Methinks I need to get him some altitude to get his basking rock closer to the UVB source(?)
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Re: Natural sunlight vs MVB or uvb bulbs

Postby MrSpectrum » Mon Nov 18, 2019 1:10 pm

MrSpectrum wrote:I'm having trouble locating it now (because I can't recall the name), but there's a YT channel owned by an Australian veterinarian who specializes in BDs.

Found it! BeardieVet
He doesn't seem to have much of a following right now (61 subscribers) but he also has a FB page.
I gotta think if he got some feedback, encouragement, & publicity, things might change.

Just watched this: Measuring bearded dragon basking UVI in the field
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