UVB lighting for reptiles: what it does and how to set it up correctly

Quick answer

For many reptiles, UVB enables vitamin D synthesis and healthy calcium metabolism. If your species needs UVB, the setup must be correct: the right bulb type, correct distance, a consistent schedule, and no glass or plastic blocking the light.

Who typically needs UVB

Many diurnal lizards and tortoises need UVB. Some species can do well without strong UVB when diet and supplementation are managed carefully, but beginners should confirm species requirements before deciding.

If you are unsure, assume UVB is needed and verify with a reputable care guide or an exotics vet.

The 4 rules that prevent most UVB problems

1. Use a reputable UVB bulb and fixture. Output varies widely.
2. Distance matters. UVB intensity changes a lot with distance.
3. No barriers. Glass and many plastics block UVB.
4. Replace on schedule. UVB output declines even if the bulb still lights up.

Placement: where it should go

• Place UVB so the reptile can choose exposure.
• Provide hides and shaded areas.
• Align UVB with the basking area for many diurnal species.

Schedule: keep it simple

• Use a timer.
• Keep a consistent day-night cycle.
• Avoid leaving lights on 24/7.

Replace schedule

Different bulbs have different lifespans. Use the manufacturer guidance and put a reminder in your calendar.

FAQ

Can I put UVB through a screen top?

Some screens reduce UVB intensity. Placement and distance become even more important.

Can UVB be "too strong"?

Yes. That is why distance, shade, and correct bulb choice matter.

Do I still need calcium supplements if I have UVB?

Often yes. Supplementation depends on species and diet. Do not guess, confirm a species-specific plan.

Next step

Want a beginner-friendly setup plan based on your space and schedule?