How to Choose Reptile Terrarium Lighting: UVB, Heat and LED
Zoo Med ReptiSun 10.0 T5 HO UVB Fluorescent Bulb delivers the strongest desert-strength UVB output for most keepers. Arcadia Reptile T5 Forest 6% UVB Bulb suits forest and tropical species better. Exo Terra Solar Glo Mercury Vapor Bulb combines UVB, heat and visible light in one fixture.
Zoo Med ReptiSun 10.0 T5 HO UVB Fluorescent Bulb is the strongest general pick for desert species like bearded dragons and uromastyx. Its high T5 HO output reaches across wider tanks than a standard T8 tube. That reach comes with a catch: it needs a T5 HO specific fixture, not a standard T8 hood.
UVB strength, basking heat and visible spectrum come from different bulb types that rarely overlap, which makes reptile lighting confusing. We compared manufacturer-listed UVB percentages, wattage, fixture compatibility and owner feedback on bulb lifespan to match each pick to a specific species or setup.
The best picks, ranked
Zoo Med ReptiSun 10.0 T5 HO UVB Fluorescent Bulb
This T5 High Output tube targets desert and arid species that need strong UVB to metabolize calcium. Its 10.0 rating pushes UVB further into taller or wider enclosures than a T8 bulb at the same percentage. Zoo Med recommends swapping it out on a 12 month cycle, even though the tube still lights up after that.
Pros
- High UVB output suits desert species like bearded dragons and uromastyx
- T5 HO design pushes usable UVB across wider or taller tanks than T8 tubes
- Manufacturer states a consistent 12 month replacement window
Cons
- Requires a T5 HO specific fixture, won’t work in standard T8 hoods
- 10.0 output can overwhelm shaded tropical or forest tanks
Arcadia Reptile T5 Forest 6% UVB Bulb
Shade dwelling species need lower, gentler UVB than desert reptiles, and Arcadia built this tube around that need. Its 6% output suits crested geckos, day geckos and forest skinks kept in planted or bioactive enclosures. T5 HO technology still carries that output deeper into the tank than a comparable T8 tube.
Pros
- 6% output matches shade dwelling species like crested geckos and forest skinks
- T5 HO output still reaches into deeper, planted bioactive setups
- Lower UVB reduces risk of eye or skin irritation in sensitive species
Cons
- Not strong enough for desert baskers such as bearded dragons
- Needs a T5 HO fixture, adding cost if the tank only has a T8 hood
Zilla Halogen Basking Spot Bulb
Unlike the bulbs above, this halogen spot bulb is a dedicated heat source with no UVB output, meant to pair with a UVB tube. Halogen construction produces a tighter, hotter basking spot than a standard incandescent bulb at the same wattage. It screws into any dome fixture with a standard or ceramic socket.
Pros
- Halogen construction creates a tighter, hotter basking spot than incandescent bulbs
- Available in several wattages to match different tank sizes
- Works in any standard dome fixture without special wiring
Cons
- Produces no UVB, so it must be paired with a separate UVB tube
- Some owners report shorter bulb life than a full year of use
Fluker’s Repta Clamp Lamp Dome Fixture
This clamp lamp fixture holds a basking or heat bulb rather than a UVB tube. It mounts to a shelf, stand or screen top without drilling. Its 5.5 inch dome uses a ceramic socket rated for higher wattage than a plastic socket allows, making it a solid companion fixture next to a UVB tube on smaller enclosures.
Pros
- Spring clamp mounts to shelves, stands or screen tops without drilling
- Ceramic socket handles higher wattage heat bulbs than plastic sockets
- Compact 5.5 inch dome suits smaller or nano enclosures
Cons
- Dome size limits it to smaller bulbs, not large mercury vapor bulbs
- No internal reflector coating, so some listings mention uneven heat spread
Exo Terra Solar Glo Mercury Vapor Bulb
One bulb does three jobs here: the self-ballasted Solar Glo produces UVA, UVB, heat and bright visible light together. That combination simplifies wiring on enclosures built for only one fixture. Mercury vapor construction also projects UVB further into tall, naturalistic terrariums than a fluorescent tube.
Pros
- Combines UVB, heat and visible light in a single bulb
- Reduces the number of fixtures needed on single-bulb enclosures
- Mercury vapor design projects UVB further into tall terrariums
Cons
- Cannot be used with a dimmer and needs a ceramic socket rated for its wattage
- Costs more per bulb than a standard UVB fluorescent tube
Zoo Med ReptiSun LED and UVB Terrarium Hood
A full spectrum LED strip sits next to a T8 UVB slot inside this hood, letting keepers run daylight LEDs and UVB from one fixture. Its hinged top allows bulb access without lifting the whole hood off the tank. The hood is sized for standard 24 inch glass terrariums.
Pros
- Houses a full spectrum LED strip alongside a T8 UVB bulb in one hood
- Hinged top allows bulb access without removing the whole fixture
- Fits standard 24 inch glass terrariums without extra hardware
Cons
- UVB bulb is sold separately from the fixture
- Only fits 24 inch tank widths, not adjustable for other sizes
Repti Zoo LED Full Spectrum Terrarium Light
Full spectrum LEDs replace fluorescent tubes in this fixture, aimed at supporting live plants and natural coloration rather than delivering UVB. Extendable brackets fit tanks from about 18 to 24 inches wide. Low wattage draw keeps it running cheaper than a comparable fluorescent hood.
Pros
- Extendable brackets fit tanks from about 18 to 24 inches wide
- Full spectrum LEDs support live plant growth in bioactive setups
- Low 12W draw costs less to run than a fluorescent hood
Cons
- Emits no UVB, so reptiles still need a dedicated UVB bulb
- Light output favors plants and viewing rather than basking heat
How to pick the right one
Understanding UVB Output and Why It Matters UVB bulbs carry a number or percentage such as 5.0, 6%, 10.0 or 12%, and that figure shows how much UVB radiation the bulb emits. Desert and arid-adapted species like bearded dragons and uromastyx generally need higher output, in the 10.0 to 12% range, to synthesize vitamin D3 properly. Forest and shade-dwelling species such as crested geckos need much less, often 5.0 to 6%, since intense UVB can irritate their eyes and skin. T5 High Output tubes push UVB further into a tank than T8 fluorescent tubes at the same percentage, which matters most in taller enclosures.
Basking Heat Versus Ambient UVB Light Most UVB fluorescent tubes generate little usable heat, so a separate basking bulb such as a halogen spot handles temperature control. Halogen basking bulbs create a tighter, hotter spot than a standard incandescent bulb at the same wattage, letting keepers dial in a specific basking zone. Mercury vapor bulbs like the Exo Terra Solar Glo combine UVB and heat in one bulb. That simplifies wiring on single-bulb enclosures but removes the option to adjust each separately. A thermostat paired with the basking bulb helps prevent overheating regardless of which heat source is chosen.
Matching Lighting to Desert, Tropical and Forest Species Desert species housed in open, brightly lit tanks generally do best with a 10.0 or 12% T5 HO bulb mounted close to the basking branch. Tropical and forest species living in planted, humid enclosures need lower UVB output paired with full spectrum LED lighting that also supports live plant growth. Nocturnal species or those that spend most of their time hidden may need only a low UVB bulb or none at all, depending on species-specific care sheets. Bioactive setups with live plants often combine a full spectrum LED fixture with a separate low-output UVB tube rather than one all-in-one bulb.
Bulb Replacement Schedules and Tank Size Limits Fluorescent and mercury vapor UVB bulbs lose effective output well before they burn out. Manufacturers recommend replacing them roughly every 12 months even when the bulb still lights up. Halogen basking bulbs often need replacement sooner, based on owner reports of filament wear over several months. Fixture length limits choices too, since a 24 inch hood only accepts 24 inch tubes, so measuring the tank before buying avoids a mismatched purchase. Tanks longer than about 36 inches may need two fixtures or a higher-output bulb to keep UVB levels consistent across the whole basking area.
Side by side
| # | Model | UVB Output | Best for | Score | Price |
|---|---|---|---|---|---|
| 1 | Zoo Med ReptiSun 10.0 T5 HO UVB Fluorescent Bulb | 10.0 (desert strength) | Best overall | 9.4 | Check price |
| 2 | Arcadia Reptile T5 Forest 6% UVB Bulb | 6% (forest strength) | Best for tropical or forest species | 9.1 | Check price |
| 3 | Zilla Halogen Basking Spot Bulb | Halogen basking spot, no UVB | Best basking heat lamp | 8.8 | Check price |
| 4 | Fluker’s Repta Clamp Lamp Dome Fixture | Clamp lamp dome, ceramic socket | Best value fixture | 8.6 | Check price |
| 5 | Exo Terra Solar Glo Mercury Vapor Bulb | Combined UVA, UVB, heat and visible light | Best all-in-one UVB and heat | 8.4 | Check price |
| 6 | Zoo Med ReptiSun LED and UVB Terrarium Hood | Hood with LED strip plus T8 UVB slot | Best fixture or hood combo | 8.2 | Check price |
| 7 | Repti Zoo LED Full Spectrum Terrarium Light | Full spectrum LED, no UVB | Best budget LED for live plants | 8.0 | Check price |
Questions worth asking
How do I know what UVB percentage my reptile needs?
Check a species-specific care sheet first. Desert species like bearded dragons typically need 10.0 to 12% UVB, while forest species like crested geckos need closer to 5.0 to 6%.
Is a UVB bulb the same as a basking bulb?
No. Most UVB fluorescent tubes produce little heat, so keepers pair them with a separate basking bulb like a halogen spot, unless they choose an all-in-one mercury vapor bulb such as the Exo Terra Solar Glo.
What is the best reptile lighting for bearded dragons?
A high-output UVB bulb like the Zoo Med ReptiSun 10.0 T5 HO paired with a halogen basking bulb such as the Zilla Halogen Basking Spot covers both UVB and heat needs for desert species.
Can I use a mercury vapor bulb in a regular dome fixture?
Mercury vapor bulbs like the Solar Glo need a ceramic socket rated for their wattage. A plastic dome socket can melt or fail under the heat these bulbs generate.
How often should reptile UVB bulbs be replaced?
Most fluorescent and mercury vapor UVB bulbs lose effective UVB output after about 12 months, according to manufacturer guidance, even though the bulb keeps producing visible light.
T5 HO vs T8 UVB bulbs, which is better?
T5 High Output tubes push usable UVB further into a tank than T8 tubes at the same rated percentage, making T5 HO a better fit for taller or wider enclosures.
Do LED lights provide UVB for reptiles?
Standard full spectrum LED fixtures like the Repti Zoo LED light do not provide UVB. Reptiles that need UVB still require a dedicated fluorescent or mercury vapor bulb.
What size fixture do I need for a 24 inch tank?
A 24 inch hood, such as the Zoo Med ReptiSun LED and UVB hood, matches a 24 inch tank width. Measuring the tank before buying prevents an undersized or oversized fixture.
Are UVB bulbs necessary for nocturnal reptiles?
Many nocturnal species need little or no UVB, but check a species-specific care sheet since some still benefit from low-level exposure during active hours.
Final word
Zoo Med ReptiSun 10.0 T5 HO UVB Fluorescent Bulb remains the strongest choice for keepers of desert species, since its high UVB output and T5 HO reach cover larger enclosures without a second UVB bulb. Owners of crested geckos, day geckos or other low-UVB tropical species should choose the Arcadia Reptile T5 Forest 6% UVB Bulb instead, since a 10.0 bulb delivers more UVB than these species tolerate well.
