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Mercury Vapor Bulbs

Discussion in 'Habitat Lighting' started by pjrojo, Jul 15, 2013.

  1. pjrojo

    pjrojo Subscribed User Premium Member

    Today I replaced both the basking and compact full spectrum blub in one of my Bearded Dragon enclosures with a 125w Exo Terra Mercury Vapor Bulb, This will be my first go around with a mercury vapor blub, Based on all of the reading I've done this 'all in one' blub replaces both the basking and compact full spectrum blubs but can/has it passed the HC member test :)

    Will Spike be okay with this type of blub?
     
  2. Katsura

    Katsura Elite Member

    They still sell stuff with mercury in it??
     
  3. DragonsKeepers

    DragonsKeepers Subscribed User Premium Member

    How close to the bulb can your dragon get? What are the overall enclosure dimensions as well?
     
  4. kriminaal

    kriminaal HH Block Leader Staff Member Premium Member

    Yes, you have to watch the 'specs' on each type of these bulbs as they usually don't need to be as close as other UVB sources.
    I've used MVB from reptile UV before and was quite happy with them. No experiences with the Exo Terrra ones though.
     
  5. jarich

    jarich Elite Member

    MVBs can be great in the right setting, although Exo Terra as a brand is pretty terrible. Would be much better to go with a Mega-ray, Zoo med or Arcadia brand.
     
  6. Thalatte

    Thalatte Elite Member

    I use MVBs for all not indoor tort setups, the beardie cages, Tai's rehab cage, and the box turtle cage and I love them.
     
  7. Vers

    Vers Elite Member

    Frankly the only worthwhile MVB lamps out there, based on recent testing, are Arcadia and Mega-Ray variants. The former needs a 110v->220v external step-up ballast to run the lamp here in the states. The latter seems to suffer quite a bit in the QC department, although they might have gotten better more recently. As far as ZooMed MVBs go, I've tested numerous copies and none of them performed well enough for me to recommend them.

    Personally I believe Arcadia and ZooMed T5 HO setups (in conjunction with outdoor halogen floods and daylight rated fluorescents) are the go-to choice atm. Although they don't produce as much UVA as many MVBs they do produce a better overall spectrum, are more versatile and are much more efficient. Metal halides are superior, but their cost is a bit of a turnoff for most.
     
  8. Thalatte

    Thalatte Elite Member

    Ok vers I had a question on the T5 and T8 bulbs...Are the T8's much worse than the T5's? All my fixtures are T8's so I would like to know if it would be worth my time to buy T5 fixtures.

    So Powersun MVBs are junk?
     
  9. DwarvenChef

    DwarvenChef Elite Member

    In my design for a large sceloporus enclosure I have been looking for proper dayural lighting. I'm still unhappy with my knowledge of modern lighting for this and would love to find some data that will help me understand and implement the correct levels of lighting.

    Books or links suggestions would be handy :)
     
  10. Vers

    Vers Elite Member

    T5 HO (High Output) UVB fluorescents perform significantly better than T8 variants, both in terms of output (spectrum, UV and lumens) and lifespan. T8 fluorescent bulbs aren't bad, per se, but they are not the best choice for animals that require a ton of UV; In most cases, T5 HOs would be superior. Typically T8 fluorescents will run effectively for 6-8 months before UV levels deteriorate past the point of actual usefulness, which is why it's recommended to replace them at the 6mo mark. On the flip side, I have been running some T5 HO bulbs for over a year and a half and have seen ~30-40% dropoff in performance over that period and even now they are still producing respectable UVB levels...levels that are typical of or better than new T8 bulbs with the same UV 'rating'. In the end, yes, I believe the transition from T8 to T5 HO would be worthwhile. You will be receiving bulbs with both a larger lifespan AND better overall performance in terms of UV output for essentially the same price per bulb. It's really a no-brainer. There is one caveat, however, that you must take into account: these bulbs act more like MVB lamps in terms of UV output than standard NO (Normal Output) fluorescent UVB bulbs--they must be implemented correctly in order to avoid any issues. They also generate a lot more heat...enough to throw temps off in an enclosed area.

    Back before I made the switch I was a big proponent of MVB lighting, specifically ZooMed's PowerSun lamps. That all changed when I received my UVB meter (Solar Meter 6.2). I tested several bulbs, both new and burned in, and they all generated lackluster UVB levels (more on that here). Since that thread I've gained a much better understanding of how these and various other UVB bulbs/lamps function (thanks to Frances Baines), including learning about UVB:UVI ratios as well as the difference between shortwave and longwave radiation. Since I don't have a Solar Meter 6.5 I don't know what ratio the PowerSun lamps were producing but I can tell straight away that it would be way off balance. Here is the response I received from Frances soon after I took comparison readings...link
     
  11. Vers

    Vers Elite Member

    Not a book, but I would seriously recommend joining the 'UV Meter Owners' Yahoo group and refer to this thread for links to some very good light reading.
     
  12. jarich

    jarich Elite Member

    Hahaha, I see what you did there. ;)

    Forgot you were here Matt. Thats interesting about the Powersuns. Ive always thought of Zoomed as a good brand for lights, so I put them in with my previous post without actually having any experience, to be honest. I know their fluorescents are great so I mistakenly assumed their MVBs would be also. Thanks for correcting me there.

    As for the other brands, I know from testing that they have very high UVB output, and that there is concern over the UVB:UVI ratio. Ive questioned Francis in the group as Im not sure I quite grasp and/or agree with her as regards the detriment of MVB light. I know my MegaRay puts out about twice as much UVB as my Arcadia T5s at distance, and that it is the shorter wavelength that makes up the greater portion of that UVB. I just dont agree that the longer wavelength UVB alone is responsible for the limiting factor of the Vit D metabolites. Again, it could just be my lack of knowledge, but everything I have read states that all wavelengths of UVB, and UVC even, are responsible for the degradation of Vit D metabolites. Im sure its always better to try to mimic the more natural wavelength of the sun if possible, but I still dont see why the MVBs would be negative for their higher concentration of shorter wavelengths. As you know, they arent short wavelength, just on the shorter end of the spectrum; and still well within the healthy range of UVB.
     
  13. Vers

    Vers Elite Member

    The thing is you cannot compare MVB and fluorescents directly since they function very differently. How, may I ask, did you test...or, more importantly, which tool(s) did you use to take readings with?
    I can't agree or disagree with you here because like you my knowledge of the D3 synthesis process is relatively limited. What studies/sources have you read and were any based on Vit D3 synthesis in reptiles?
    I believe this to be ideal, but again my knowledge of the subject isn't polished enough to make a sound determination.
    I don't really see it as negative, I just think T5 HO bulbs produce a better overall spectrum (although they are comparatively weak in the UVA department) and are far more versatile
     
  14. jarich

    jarich Elite Member

    Ya, of course but there are ways to still compare their outputs as it pertains to this discussion. As I'm sure you know, the disadvantage of the MVBs is that the spectrum produced is very much a series of high peaks whereas with fluorescents you have a more continuous spectral output. But if one gives me a reading of 90 and the other 40 on my Solarmeter 6.2, and the purpose is UVB and subsequent Vit D synthesis then I'm likely to pick the sharper tool for the job.

    Incidentally, any idea why it was so hard to get a 6.5 for so long? I finally got my hands on one but had to wait for awhile and it wasn't cheap.

    Haha, how long have you got? My wife was threatening me with a filing cabinet for my birthday present so she wouldn't have to deal with stacks of articles and journals all over anymore. The reptile specific ones are much fewer but a lot of the Vit D cycle is common pan-species/genus/family thankfully, or at least appears to be.

    Ya I see what you mean, and its my initial instinct as well, but I think we've come to see lighting as a much more complex issue; one that is not easily answered by any single light. Plus Arcadia groupies are like a weird cult sometimes. Haha ;)

    Have you got any HIDs? I'm looking at trying those next.
     
  15. Vers

    Vers Elite Member

    That's precisely what I mean though...they cannot be directly compared, especially not without factoring in the UVB:UVI ratio. That requires taking readings from both the 6.2 and the 6.5 and even then it's not entirely cut and dry. For instance when I tested my PowerSun lamps against my T5 HOs the PSs were generating a measly 20 uW/cm2 while the Arcadias were putting out over 200 uW/cm2 at approximately the same distance (IIRC). This may seem like a hugely disparaging comparison however the PSs, while weak, may not have been performing as bad as they appeared. It's because MVBs operate at a different wavelength (more shortwave) that the UV generated is essentially 'magnified', for lack of a better term. It's because of this that comparing the two can be very tricky...at least that's how I understand things.
    I had noticed that they were out of stock at one time, but I had no idea they remained so for a while. I know LYR has them in stock for 198.95, which while steep is significantly cheaper than many other meters out there. With that said I haven't really had the overwhelming need for one since I've been content with my Arcadias and readings are already readily available. Perhaps if I switch to something else I'll consider picking the 6.5 up.
    Haha I see. Well if you have any good ones that come to mind throw them my way...perhaps I've yet to read them.
    Exactly. All I need is a bulb that produces a good amount of UVA to balance my Arcadias out...but then again perhaps I'm being too large a perfectionist.
    Haha I'm not convinced it's limited to Arcadia users so much as it is lighting junkies. 'Round here I'm sure most consider me a weirdo in that respect...perhaps just as much as my stance on desert herbivore diets.
    Since I have been so happy with my current lighting setup I haven't even thought of dealing with anything new...especially pricey HID lighting. Have you stumbled upon anything worth checking in to?
     
    Last edited: Jul 16, 2013
  16. jarich

    jarich Elite Member

    Well, yes and no I think. Its not that MVBs operate at a different wavelength, they just have a higher concentration of the shorter wavelengths, in very specific peaks. They spike a bit around 297, a further spike at 303, and then again a larger spike up around 313. Whereas the fluorescents you dont get much of the shorter wavelengths until after the 313 peak, which leads to a more gradual higher amount at the longer wavelengths around 320. Since the majority of Vit D production happens between 295 and 305, that means that technically the MVBs are better equipped to stimulate that production, even if the overall reading from your 6.2 is lower (as you know the 6.2 reads all UVB and not just the narrow width that is responsible for most Vit D production). Again though, you only get the spikes at certain points from the MVB, whereas you get a more full range from the fluorescents. Frances has said that she thinks the lack of the higher end of the UVB spectrum is a problem for MVBs in limiting the Vit D production cycle, but again Im not sure why that is. She is the expert, of course, but everything I read is contrary to that, so I dont know.

    Ya, LYR was and still is out, as I wouldve rather bought from them. They always have a much cheaper price. I could only find them direct from Solarmeter for about $50 more.

    No, I think you are right. The more I read about UVA, the more I think that both that and the total lumens (usually the same bulb increases both) are another important facet of lighting. Its one of the other reasons I started looking into the HIDs.

    Just around here? ;)

    I picked up a fixture/ballast on CL for a very good price, but the bulb it came with was just for plant growth so Im looking into UVB/UVA specific bulbs now. So far I think the only option I could use it on is my bearded dragon, as the heat it produces makes mounting it inside an enclosure impossible.
     

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