Coil UVB vs T5 Linear UVB for Bearded Dragons
Why a compact coil bulb cannot light a 4 foot enclosure, what UV index a bearded dragon actually needs, and how to mount a linear tube correctly.
The short version
Buy the linear T5 HO tube. A bearded dragon is a high UV desert species that needs a UV index of roughly 3.0 to 4.0 at the basking surface, spread across a basking zone it can move through. A coil bulb produces a narrow, intense column directly under itself and nothing useful a few inches to either side, so the animal has almost no gradient to work with. Older compact designs were also associated with eye irritation in reptiles. The tube should run about two thirds to three quarters of the enclosure length over the warm end.
At a glance
| Zoo Med ReptiSun 10.0 HO T5 Lamp, 34 inch | Zoo Med ReptiSun 10.0 Mini Compact Lamp | |
|---|---|---|
| UV footprint | Long band across the warm end | A narrow column under the bulb |
| Suits a 4 by 2 by 2 foot enclosure | Yes, with the right length | No |
| Gradient the animal can choose from | Good | Almost none |
| Replacement interval | About 12 months | About 6 months |
| Needs a separate fixture | Yes, a reflector fixture | Screws into a dome |
| Running cost over a year | Higher up front, lower per year | Cheap, replaced twice as often |
Choose the Zoo Med ReptiSun 10.0 HO T5 Lamp, 34 inch if…
Choose the linear T5 HO tube for any bearded dragon enclosure. Mount it inside the enclosure or directly above an open section rather than resting it on mesh, because a standard screen top absorbs a large share of the UVB passing through it, often around a third or more. Use a reflector fixture, since a bare tube throws most of its output at the ceiling. Set the distance so the basking surface sits in the right UV index band, then write the installation date on the tube in marker.
Check Zoo Med ReptiSun 10.0 HO T5 Lamp, 34 inch on Amazon
Choose the Zoo Med ReptiSun 10.0 Mini Compact Lamp if…
There is no bearded dragon setup where a compact coil is the better choice. If you have inherited one, the honest interim advice is to keep it well away from the animal's face, keep the basking spot within the coil's very small effective area, and replace it with a linear tube as soon as you can. Compact lamps are sometimes sold as suitable for small enclosures, but the enclosure a bearded dragon needs is not small.
Check Zoo Med ReptiSun 10.0 Mini Compact Lamp on Amazon
Related
- Arcadia 12 Percent vs 14 Percent UVB
- UV Meter vs a Replacement Schedule
- Bearded dragon lighting guides
Comparison based on published manufacturer specifications and the general consensus of owner reports. We have not tested these products side by side. Confirm current specifications and prices before buying. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
Deciding on a specific model? We review the Arcadia LumenIZE ProT5 14% Dragon 36 inch review, Arcadia LumenIZE ProT5 12% Desert 36 inch review and Zoo Med ReptiSun 10.0 T5 HO UVB lamp review in full.
Editor's Pick · Affiliate link
A T5 10.0 UVB Fixture, the One Thing You Cannot Skip
Metabolic bone disease is the most common preventable illness in captive bearded dragons, and it comes down to inadequate UVB. A linear T5 tube across the basking side does what a coil bulb cannot, and the tube needs replacing roughly annually even when it still lights up.
Frequently Asked Questions
What UV index should a bearded dragon bask in?
Bearded dragons are usually placed in the highest UV group used for pet reptiles, with a basking zone target around a UV index of 3.0 to 4.0 and lower readings across the rest of the enclosure so the animal can choose. The number depends on lamp to animal distance, not on the percentage printed on the box, which is why two people using the same lamp can end up with very different exposure. If you cannot measure it, follow the lamp manufacturer's published mounting distance for your exact model and fixture.
How often does a UVB tube need replacing?
T5 HO tubes are generally replaced at about twelve months and T8 tubes at about six, depending on the manufacturer's guidance. UVB output falls long before the tube stops producing visible light, so a lamp that looks fine can be doing nothing useful. Date the tube when you fit it. This is the single most common reason a dragon on a correct looking setup develops metabolic bone disease.
What are the signs of metabolic bone disease?
Tremors or twitching, weakness in the back legs, a swollen or soft lower jaw, a kinked spine or tail, reluctance to climb, and bones that look bowed. It is caused by inadequate UVB, inadequate calcium or both, and it is a veterinary emergency in its early stages as much as its late ones. Take the animal to a vet who sees reptiles, and take a photograph of your lighting setup with you.
Need more help with your bearded dragon?
Browse our guides by topic to find practical solutions.
Wellness Planner: $39