For the purpose of this little post, I’ll be aiming the whole piece at Bearded Dragon (Pogona vitticeps) setups in particular.
There seems to be a common trend in many Bearded Dragon facebook group’s (and social media in general) of poor advice given regarding the placement of UVB within the setup. More so, a T5 UVB tube.
So let’s keep the explanations as simple and easy to understand as we can. Of course with the needed links and other relevant info for you to continue your own research.
Now we ALL should know by know by now that the coil UVB bulbs are simply not efficient enough for our Bearded Dragon’s evolutionary UV needs. So no-one should be using them. No excuses will ever warrant their use here. (They are actually ideal for smaller frog setups for example. So definitely still a place within the hobby for such bulb’s)
The issue being, and its often regurgitated as, “As T5 is stronger, it can sit on-top of the mesh screen!”.
And Sure, it can, for some species that require lower levels of UVB exposure. Geckos for example. Even many Chameleon keepers do such.
But our dragons sit within the high exposure range while basking according to the data collected over a number of years by Professor Gary Ferguson of Texas Christian University, using data gathered with Solarmeter Model 6.5 UV Index Meters (related cited article available here), and of course millions of witnessed accounts.
So lets take the recommended distances required for our T8 and T5-HO tubes and their use within our Dragon set-ups according to the world’s leading authorities on their usage, Arcadia reptiles. Thus achieving the required UV-Index as the species needs per the previously mentions Ferguson Zones.
And the below is ALWAYS under the assumption you are using a reflector for the UV tube;
- For a T8 (Arcadia 12% or ZooMed 10.0) – 10 to 12 inches from tube to Dragon’s back, at the closest point.
- For T5-HO (Arcadia 12% or ZooMed 10.0) – 12-18 inches from tube to Dragon’s back, at the closest point.
often the issue arises when keepers have woefully inadequately sized enclosures. These 40-gallon breeder tanks that they are being told are perfect for an adult dragon. Wrong. They are way to small.
An adult will need at-least a 4ftx2ftx2ft, bigger preferably. This is around 120-gallons I believe.
Here in the UK, we can source great sized wooden enclosures with ease. I realise it’s thought to be harder for USA/Canadian keepers. But on researching, it’s not. There are many companies that will make a custom enclosure (check my facebook group for many examples)
Realistically, you are going to want at least 18 inches in height for the correct and safe T5-HO lighting setup inside the enclosure. But as stated, 24 inches (2ft) will offer the best option for allowing a good substrate depth & decor, etc.
If you can’t get that needed minimum of 18″ in height for the T5-HO use, then you should use a T8 equivalent. Thus giving you better options for substrate depth & decor.
The “theory” of using the T5 on mesh because its stronger is not only potentially dangerous. But idiotic without the use of a Solar Meter 6.5 to measure the index with the setup.
With mesh blocking 30% to 50% of UV getting through to the set-up surface, basically, you are guessing the amount that dragon is getting. And guess work with something so vital as UVB is a danger to the health and wellbeing of your Dragon, as underprovision of UVB is just as dangerous as overprovision. Both can lead to a slow and often painful ailments for the Dragon.
Obviously mesh density WILL affect such. The larger the mesh holes, the more UV that will penetrate.
But with the commonly used ZooMed & Exo-Terra type enclosures it’s far to dangerous to use UVB on-top.
Yes, T5 is far better technology. But again, without those ‘safe’ and required distances as already stated for its placement inside a setup, you’ll need to use a T8 inside the setup. Simple as that really
I did a simple experiment showing the effects of mesh blocking UVB on my YouTube channel. The short video is here.
For some further T5/T8 reading, here are a couple of my blog articles for Northampton Reptile Centre on the related above subject.
Feel free to share the post within those groups/pages that honestly don’t understand the facts on this subject. As here you have linked proof based on cited references.
If they argue against that…..then you are better off away from such groups/pages, as they don’t deserve YOU.
Published author of herpetoculture.
Featuring articles on many species within,
Practical Reptile Keeping magazine (some linked on site as .pdf files).
Canadian Hobbyist magazine.
Also, Reptile/Amphibian blog article writer for;
Northampton Reptile Centre
Exotic Direct (links on this site)
Public talker at Reptile meetings, for various organisations.
And founder of several huge Reptile and Amphibian related Facebook groups (links on this site)
Reptile Reports – “Lizard Personality of the year” 2016 – 2017