Good lightbulbs Bad lightbulbs

[reptylefreek]

Every time I come across a thread about light bulbs I always see every one claiming this brand is the best and this one has the highest out put of UV and so on. There was a discussion on this forum about how much UV a tort really needs on a daily basis and it got me thinking. I understand that some brands of bulbs might last longer (how do you really know it is still putting out UVB?) but as long as the bulb puts out some UVB wouldn't that be sufficient? As long as it's on everyday for a certain period so the tort can soak up some rays, wouldn't it be sufficient? And if it is not sufficient, despite what the people say about their own product, how do you know if the bulb is still doing its job? I know most people say the bulbs are only good for about 6months then they are pretty much dead, but do they put out ENOUGH rays for a year. I stress the word enough because when a tort is outside in the shade it is still getting UV rays but its not the same as if directly in the sun. But that is still enough for the most part. I am not talking about heat at all, just UV rays. I would love everyones input, please

 

[Maggie Cummings]

There's a gun that you can buy that reads the UVB rays coming out of the bulb. I'm thinking basically you are asking if any UVB rays are better then none, and because you live in the Seatac area you have a lot of gray days. I have a 250 watt Trex flood that Bob has used for 2 years. I figure there's no UVB rays anymore but it's still hot and I figure that's all Bob needs because he has the option to go outside daily so all he really needs is heat to warm up after he comes in from the rain.
I'm pretty skeptical about these UVB bulbs. I only use them in the winter when my smaller tortoises can't go outside. In spring and summer if they can get an hour or 2 outside I figure that's good enough, and they all seem to be fairly healthy and content...or is it me that's content???

 

[reptylefreek]

I like that answer maggie thank you. Marlin is still too small to be outside on his own. So I try to get him outside when its not raining. I think you said you had a storm come through Oregon, well it's hit us or something because the last two days we have had outragous thunder and rain and hail. It is really now officially fall

 

[Madkins007]

Check out this comment I just posted a bit ago: http://tortoiseforum.org/thread-5893-post-91359.html#pid91359

It seems that some bulbs may not be worthwhile even with good UVB levels posted.

 

[tortoisenerd]

This site is an amazing resource: www.uvguide.co.ukm This site has published output on many bulbs, which is where I have found that the T-Rex and Mega Ray (same bulb) have the highest output. From personal reviews online, I have also determined that they seem to have the best positive customer reviews for liking the bulb (the T-Rex more so than the Mega Ray) and have been said to have less of a chance of blowing early than some other brands (The T-Rex more so than the Mega Ray). I had a Mega Ray blow out early so I'm trying on the T-Rex now. It was cheaper for me too.

Yes, a UV meter will tell you the bulb output. Your vet or a local tort club may have one for you to borrow. Otherwise, you should go by the rules of thumbs based on research: toss a tube after 6 months and a MVB after 12 months. Many have said that a tortoise likely only needs a small amount of UVB exposure. If you are sure they are out in the sun without clouds and hides, than great. For an indoor tortoise I am wary to leave the UVB on less than the full day as I can't predict when my little guy will chose to bask, and when not. With the bulbs, the tort has to be at a certain spot under them to get sufficient UVB, unlike the sun I believe, so having the bulb on for a sufficient number of hours a day seems more important in my opinion. See the diagrams on the link above for the specific bulbs showing the radius and height of the UVB output.

I have heard some that chose to have only a light bulb on for parts of the day with the MVB only on at midday. I do not feel there is a risk of too much UVB (it does not exceed what the sun puts out, and the only risk could be dryness, ie, the "cooking" effect) and choose to have a 100 watt T-Rex MVB on for 12-14 hours a day on my yearling Russian. I chose the MVB as its output simulates the sun and I feel that is better than the low output of the tubes. I do not believe in having "enough" UVB, but want the best for my tort. I imagine this is easier with one tort than those that have many. I try to simulate his wild environment as much as I can. Buying a $40-50 bulb once a year is a small expense in his health and longevity.

 

[Madkins007]

One thing to remember- UVB output is not the end of the equation. Vitamin D3 is processed mostly by light at 295 nanometers, and production drops off as the wavelength varies from that point. Just because a bulb puts out UVB, it may emit anywhere from 280 to 320 nanometers.

Dr. Mader, in "Reptile Medicine and Surgery" discusses some research by a G. H. Gehrmann in which they actually exposed some 'pro-vitamin D3' to various fluorescent bulbs and measured how much of it was actually converted by the bulbs to 'pre-vitamin D3'. The results are fascinating, and quite different than what UVGuide.co.uk discusses.

Check out the link I posted a couple posts ago.

 

[webskipper]

I have had great results using the reptisun 10.0 UVB fluorescent lamps.

My Snaps had hard shells and the pond plants in the aquarium flourished.

I am thinking of getting a trex lamp for my first Tort table. What fixtures are recommended for these lamps? 8" dome 10" dome?