LED UVB lighting

DonnaG

Member
Right now I am using a T5 HO 39 W 34" Reptisun 10.0 UVB tube light. Both of my sons can see it flicker; but, I can't. Even if I stare at it for several minutes, I do not see it flicker. If it is flickering, does that mean it needs to be replaced?

I was watching Dav Kaufman's Reptile Adventures and heard them mention the lights from VivTech; so, I looked this company up and found lighting that appears to be suitable for bearded dragons. Here is the link to the product page:

Does anybody in the forum have experience using these lights? If I purchased this brand of light how many would I need? Paki's enclosure is approximately 2 x 2 x 4 feet. The 34 inch tube light that I'm using right now covers more than half of his enclosure. But, this is a hard light to find locally. I would have to order on line. The store that I got the current tube light from is out of stock and I don't know when it will get new stock.
 

KarrieRee

BD.org Sicko
Right now I am using a T5 HO 39 W 34" Reptisun 10.0 UVB tube light. Both of my sons can see it flicker; but, I can't. Even if I stare at it for several minutes, I do not see it flicker. If it is flickering, does that mean it needs to be replaced?

I was watching Dav Kaufman's Reptile Adventures and heard them mention the lights from VivTech; so, I looked this company up and found lighting that appears to be suitable for bearded dragons. Here is the link to the product page:

Does anybody in the forum have experience using these lights? If I purchased this brand of light how many would I need? Paki's enclosure is approximately 2 x 2 x 4 feet. The 34 inch tube light that I'm using right now covers more than half of his enclosure. But, this is a hard light to find locally. I would have to order on line. The store that I got the current tube light from is out of stock and I don't know when it will get new stock.
I have never heard of the light you posted link for - for a UVB most on this board recommend these
Zoo Med w/ a Reptisun 10.0 T 5 ---- Arcadia Pro T 5 12% bulb or a Sunblaster Nano Tech those come w/ a bulb --
as far as the flickering I am thinking its the fixture BUT I would get a new bulb before getting a new fixture if a new one does the flickering its the fixture
 

CooperDragon

BD.org Sicko
Staff member
Moderator
I've heard of these, but haven't seen any test results from them. Since they are new, I'd probably consider them to be experimental until I have more information about them. I agree with Karrie in that it's probably best to stick with a T5 like what you have since they have a long track record of success with Dragons. The flickering could be either the bulb or the fixture, it's hard to say. You could test the fixture using a plain T5 bulb (cheaper than a UVB light) from the hardware store and see if that has the same issue or not.
 

DorgEndo

Juvie Member
The only way to know if a UVB is working properly is to use a UV meter. Expensive but the only sure way.

As for flicker, lights all flicker. However, most people don't have the vision to see it. The power in our homes in AC for alternating current. I think UVB lights have a hertz of 100-120 where most people can see from 30-60 in frequency. Above 60 is quite uncommon but not impossible for a person to see, more possible if they are a younger person. If you record the UVB light with your phone you can probably see the flickering when viewing the video due to video compression stuffs. Then you can let your son know he sees things other people can't
 

Claudiusx

BD.org Sicko
Staff member
Moderator
It's interesting, but like Cooper stated, until it's been tested with a UV meter, we aren't going to be recommending it.

I'd love to test it out and see what UVI levels it produces with my meter. Based on the chart, it looks like it has a very narrow beam which would be less than ideal for most setups. But, I don't have (and can't justify) $80 to spend on one. Although the more I think about it, the more I want to buy it and test it. Anyone wanna put a pot together to buy one for testing purposes? Lol.

-Brandon
 

CooperDragon

BD.org Sicko
Staff member
Moderator
Tempting to buy one to test. I only have a 6.5 Solarmeter though, so I'm not sure how I'd test for µW/cm² (if needed) or to check for any dangerous range light being emitted from it. If we could put together a testing plan I might be able to scrounge up enough to buy one to add to the stockpile.
 

Claudiusx

BD.org Sicko
Staff member
Moderator
Tempting to buy one to test. I only have a 6.5 Solarmeter though, so I'm not sure how I'd test for µW/cm² (if needed) or to check for any dangerous range light being emitted from it. If we could put together a testing plan I might be able to scrounge up enough to buy one to add to the stockpile.
I'm not sure we actually need to measure µW/cm². I had a lengthy discussion with Francis, and she stated UVI is a sufficient measurement for our needs. Although I'd still like to eventually get one to be able to test both measurements, but that's definitely not in the books for me.

-Brandon
 

CooperDragon

BD.org Sicko
Staff member
Moderator
I think UVI is great for comparing the output of a bulb to the intensity of sunlight and also for determining when a bulb is losing it's output. My concern has more to do with making sure the relatively new style isn't producing anything near the harmful/uvc range. It would also be good to know if it is producing spikes in certain values, or has a relatively smooth curve throughout the UVB range. I recall some discussions about this sort of thing in the advanced discussion area at some point, but I'm not sure where that thread went (or exactly when it was).

Edit: I think these may be the threads I was thinking of:
T5 hood and LED?

Full spectrum lighting
 
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Claudiusx

BD.org Sicko
Staff member
Moderator
Well the manufacture specifically states it produces no UV-C, but do we take them at their word? Yes we had a lengthy discussion about UVI vs. µW/cm² and Francis chimed in to clear the air. I still have her email to me, I'll post it here:
Subject: Re: UV Index and microwatts/cm2 Hey, Brandon,Good to hear from you.Questions are always worth answering, and yours are very good ones... The whole UVI vs. uW/cm2 thing has been rolling on for many years. It was back in 2006-7 when we first noticed something weird... that although morning sunlight in Australia (for example... and yes I have been to Oz, I LOVED my all too short 5 weeks travelling mainly the west and north (Brisbane, Hervey Bay, Cairns, Daintree, Darwin, Kakadu, Alice Springs, Adelaide, Flinders Ranges, with my meters) would easily give readings of 400 uW/cm2 and above, and never harmed anything, certain lamps gave readings of only 50 uW/cm2 and caused horrific photo-kerato-conjunctivitis, even skin "burns", shock and death. Until we realised that if you measured the UV Index from these lamps, you were getting ratios of 10:1! i.e., 50 uW/cm2 was UVI 5! and when people were setting up the lamps to match their Solarmeter 6.2 "sun" readings of 300 - 400 uW/cm2, they were putting UVI 30 - 40 over their reptiles!Then we got spectrometer analysis of these lamps, and found out what was happening. The lamps were emitting enormous amounts of really short-wavelength UVB, almost UVC... and very little long-wavelength UVB. The shorter the wavelength, the fiercer the rays...only very small amounts of borderline UVC will have the same effect as a very large amount of long-wavelength UVB.Now, the UV Index meter only "sees" short-wavelength UVB, because those are the "sunburning" wavelengths, also the wavelengths that make vitamin D3. So it gives realistic readings for D3 synthesis, and if readings are high, then also, warns against burns and eye damage.But the total UVB measured by the Solarmeter 6.2, includes ALL the short and long wavelength UVB... Sunlight contains far more long-wavelength UVB than short-wavelength UVB. So a solar reading might give a ratio of UVB: UVI of anything from 35:1 with an overhead sun, to 60:1 with a sun near the horizon, when most of the shorter wavelengths have been absorbed by the atmosphere.But with lamps, the exact shape of the UV spectrum determines the proportion of short- to long-wavelength UVB, and hence the ratio you get when comparing UVI: uW/cm2.Really high quality bulbs give ratios about 30:1. Slightly "stronger" than sunlight.Average ones, and most MVB lamps, are somewhere between 17:1 and 25:1.Anything below 15:1 needs careful evaluation for safety, in my opinion...Hope that helps!There's lots of detail on the 2006-7 problem on my old www.uvguide.co.uk website although sadly, I haven't found time to update that site for many years.Best wishes,Frances
So, UVI measurements would be a better indicator of potential UVC (and intensity) because it focuses more on the shorter wavelengths (which UVC is) whereas the 6.2 measures shorter and longer wavelengths to give the µW/cm² reading.

Since the shorter wavelengths are the more damaging rays, and also the wavelengths that help produce d3 synthesis, UVI is what Francis has been recommending.

So the important thing to realize here, is that low levels of µW/cm² can still have dangerously high levels of UVC, and vice versa. Since UVI is a measurement of mainly the shorter wavelengths, it's a better indicator of how "dangerous" the light is.

-Brandon
 
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