This is the lighting setup guide for baby bearded dragons aged 0–12 months. For general 0–4 month care, see our baby care guide. For general adult lighting, see our bearded dragon lighting page. For UVB product reviews, see our best UVB light guide.
The short answer
Baby bearded dragons need T5 HO UVB 10% or 12% mounted 8–10 inches above the basking spot, a separate basking bulb reaching 100–110°F on the platform, and a 10–12 hour on / 12–14 hour off photoperiod. UVB bulbs need replacement every 12 months because UV output decays long before visible light does. The biggest lighting error is assuming a baby can use the same setup as an adult — it can’t. UVB strength, distance, and photoperiod all differ [$TRAE_REF](https://reptifiles.com/bearded-dragon-care/bearded-dragon-lighting/)[$TRAE_REF](https://www.arcadiareptile.com/lighting/uv-lighting/).
[IMAGE: Top down view of baby bearded dragon enclosure lighting setup with UVB tube on top basking lamp at one end and temperature gradient from hot to cool side, source-needed, alt=”Top down view of baby bearded dragon enclosure lighting setup with UVB tube on top basking lamp at one end and temperature gradient from hot to cool side”]
UVB for babies: 5.0 vs 10.0 vs T5 HO
UVB is not optional. Without adequate UVB, a bearded dragon cannot synthesize vitamin D3, cannot absorb calcium, and develops metabolic bone disease (MBD) within months. The setup is the difference between a healthy dragon and a $2,000 medical bill.
| Setup | Strength | Mount height | Baby suitable? | Notes |
|---|---|---|---|---|
| T5 HO 12% (Arcadia / Zoo Med) | High | 8–10″ | ✅ Yes — preferred | Strongest; mount over mesh; 12-month replacement |
| T5 HO 10% (Arcadia / Zoo Med) | High | 8–10″ | ✅ Yes | Standard choice for babies; 12-month replacement |
| T8 10% (older style) | Medium | 6–8″ | ⚠️ Marginal — needs UVI meter | Older technology; shorter bulb life; less forgiving of distance |
| T8 5.0 | Low | 4–6″ | ❌ Not recommended for babies | Output too weak at safe distance; works only for adults at close range |
| Compact / coil UVB | Variable | N/A | ❌ Avoid | Inconsistent output; can cause eye issues; not recommended by herp vets |
Why T5 HO 10% or 12% for babies
Baby bearded dragons grow at 2–4 grams per day. Their calcium demand is highest in this period. T5 HO 10–12% bulbs deliver a usable UV index (UVI 3–4 in the basking zone) at a safe distance, which is the range that supports rapid growth without overexposure. T8 5.0 bulbs cannot reach that output at safe distance and are inadequate for babies [$TRAE_REF](https://www.uvguide.co.uk/).
[IMAGE: UVB strength comparison chart for baby bearded dragon showing T5 HO 10 percent versus T8 5 percent at various distances and recommended basking zone UVI levels, source-needed, alt=”UVB strength comparison chart for baby bearded dragon showing T5 HO 10 percent versus T8 5 percent at various distances and recommended basking zone UVI levels”]
Basking lamp: distance, wattage, and the 8–10 inch rule
The basking lamp produces heat only — no UVB. Its job is to create a 100–110°F surface directly under the bulb where the dragon sits. For babies, the basking platform should be 8–10 inches from the bulb. For adults, the same setup uses 10–12 inches. Bringing the baby closer delivers more heat per minute — they are smaller and lose body heat faster.
Basking wattage by enclosure size
- 20-gallon (baby starter): 50–75W halogen
- 40-gallon (juvenile): 75–100W halogen
- 75–120 gallon (adult): 100–150W halogen
These are starting points. Use a dimming thermostat or a dimmer switch and a thermometer to dial the actual surface temperature to 100–110°F for a baby. If you cannot hit 105°F at the platform, raise the wattage or lower the bulb. If you cannot drop below 115°F, lower the wattage or raise the bulb. Never guess — always measure [$TRAE_REF](https://beardeddragonhub.com/best-heat-lamp-for-bearded-dragon/”>best heat lamp guide).
Photoperiod: the on/off schedule by age
The light cycle influences sleep, appetite, brumation readiness, and hormone cycles. A consistent photoperiod is more important than the exact hours — the dragon’s body clock stabilizes with regular timing.
| Age bracket | Lights on | Lights off | Total on-hours | Notes |
|---|---|---|---|---|
| 0–4 months | 7:00 AM | 7:00 PM | 12 hours | No reduction — babies need maximum growth support |
| 4–8 months | 7:00 AM | 7:00 PM | 12 hours | Same schedule; dragon is still growing fast |
| 8–12 months | 7:00 AM | 7:00 PM | 12 hours | Stable photoperiod; reduce in winter if brumation signals appear |
| 12+ months | 7:00 AM | 7:00 PM | 10–12 hours | Adult photoperiod; can shorten to 10 hours to mimic winter |
Why a timer is not optional
Manual on/off drifts within a week. A $10 outlet timer keeps the cycle consistent to within 5 minutes — that’s enough to prevent brumation confusion, appetite swings, and sleep disruption. Use one outlet timer for the basking lamp and a separate outlet timer for the UVB tube if you want them on slightly different cycles.
Night lighting: do babies need a night heat lamp?
Mostly no. Bearded dragons benefit from complete darkness at night to maintain a healthy circadian rhythm. The exception is when the room temperature drops below 65°F — in which case a ceramic heat emitter (CHE) or a low-wattage nocturnal heat bulb (moonlight or red-free) is appropriate. Red bulbs are not recommended — bearded dragons see red light, and it disrupts their sleep cycle [$TRAE_REF](https://beardeddragonhub.com/do-bearded-dragons-need-heat-at-night/”>night heat guide).
For full detail on night heating, see our do bearded dragons need heat at night guide.
UVB bulb replacement: every 12 months
UVB output decays long before the bulb stops emitting visible light. A T5 HO bulb that looks fine on day 365 may be emitting 50% of its original UVB output. Replace UVB bulbs every 12 months regardless of how bright they look. Set a phone reminder at the install date.
Signs your UVB is failing
- Dragon starts hiding more or avoiding the basking zone
- Reduced appetite after months of stability
- Lethargy, soft jaw, or tremors — these are MBD early signs; see our MBD page
- Bulb is more than 12 months old
Glass, mesh, and placement: what blocks UVB
Standard window glass blocks nearly all UVB. Mesh tops block a variable amount (5–40% depending on hole size). Solid plastic tops block UVB entirely. Place the UVB tube under any mesh, not on top of glass. If using a mesh top, mount the UVB 8 inches below the mesh. If using an open-top enclosure (Zen Habitats PVC), mount the UVB directly inside at the recommended distance.
The basking bulb produces heat (infrared), not UVB — its placement does not affect UV exposure. Only the UVB tube’s position matters for UV.
Quick answers
What UVB do baby bearded dragons need?
T5 HO 10% or 12% tube, mounted 8–10 inches above the basking spot. Replace every 12 months. T8 and compact bulbs are not recommended for babies.
How far should the basking light be from a baby bearded dragon?
8–10 inches from the bulb to the basking platform. Use a thermometer to verify the surface temperature is 100–110°F.
How long should baby bearded dragon lights stay on?
12 hours on / 12 hours off. Use an outlet timer to keep it consistent. Last feeding should be at least 2 hours before lights-out.
Do baby bearded dragons need a night light?
No. They need complete darkness at night. If the room drops below 65°F, use a ceramic heat emitter or red-free nocturnal bulb on a thermostat — never a red bulb.
How do I know if my UVB bulb is working?
UVB is invisible. You need a UV index meter (Solarmeter 6.5) to confirm output. Otherwise, replace every 12 months and watch for MBD warning signs. Cheap UVB bulbs from non-reptile brands are unreliable — buy from Arcadia, Zoo Med, or Reptisun.
Can I use a UVB bulb and a basking bulb in the same fixture?
No. They serve different functions and need different placement. UVB tubes run the length of the enclosure; basking bulbs are focused on one spot.
What wattage basking bulb for a baby bearded dragon?
50–75W halogen for a 20-gallon starter enclosure. Use a thermostat or dimmer to dial to 100–110°F. Increase wattage if you cannot reach the target temperature.
Do baby bearded dragons need UVB every day?
Yes, daily. UVB cannot be “saved up” with longer exposure on weekends. Consistent daily exposure at the proper strength is what supports healthy growth.
Sources & review
- ReptiFiles – Bearded Dragon Lighting: https://reptifiles.com/bearded-dragon-care/bearded-dragon-lighting/
- UV Guide UK – UVB for Reptiles: https://www.uvguide.co.uk/
- Arcadia Reptile – UV Lighting: https://www.arcadiareptile.com/lighting/uv-lighting/
- Zoo Med – Lighting Guide: https://zoomed.com/reptile-lighting-guide/
- beardeddragon.org – Lighting Setup: https://beardeddragon.org/
This guide is informational and does not replace veterinary care. MBD symptoms (tremors, soft jaw, lethargy) warrant an immediate exotics vet visit. Use a Solarmeter 6.5 to verify UV output for peace of mind; otherwise follow the replacement schedule strictly.