Lighting Explained: UVB vs UVA vs Heat 💡

🔦 Why Lighting Matters

Reptile lighting isn’t just about visibility—it’s essential for your pet’s health and survival. Proper lighting affects everything from bone strength and digestion to breeding behaviour and sleep cycles. Understanding the differences between UVB, UVA, and heat will help you build a lighting system that keeps your pet thriving.

☀️ UVB – Ultraviolet B

What it does:
UVB is responsible for helping reptiles synthesize vitamin D3, which allows them to absorb calcium from their diet. Without UVB, reptiles are at high risk of metabolic bone disease (MBD).

Who needs it:

• Diurnal reptiles (active during the day) like bearded dragons, chameleons, tortoises, uromastyx, and green water dragons

• Some amphibians and diurnal lizards benefit too

Types of UVB bulbs:

• T5 HO (high output): strong, good for larger enclosures

• T8: lower output, best for smaller setups

• Compact UVB: convenient but with limited range

• Mercury Vapour Bulbs: Great for open or mesh enclosures

Replace every: 6–12 months (even if it still “works” — UVB output fades over time)

🔆 UVA – Ultraviolet A

What it does:
UVA affects natural behaviours like feeding, mating, and activity levels. It helps reptiles perceive their surroundings more like they would in the wild.

Who benefits from it:

• Nearly all reptiles and amphibians

• Especially important for diurnal species

Where to get it:
Many UVB bulbs also emit UVA, but full-spectrum daylight bulbs can supplement if needed.

🔥 Heat – Infrared & Basking Lights

What it does:
Reptiles are ectothermic—they rely on external heat to regulate body temperature, digest food, and stay active. Heat sources create basking zones, allowing them to thermoregulate.

Common heat sources:

• Basking spot lamps (halogen or incandescent)

• Ceramic heat emitters (CHEs) – heat without light, great for night

• Deep Heat Projectors – radiant heat, similar to sunlight

• Under-tank heaters (for burrowing/nocturnal species)

Use with a thermostat to avoid overheating.

⚠️ Lighting Mistakes to Avoid

• Using UVB + D3 supplements together excessively (risk of overdose)

• Letting UVB bulbs burn past their useful life

• Not providing a gradient (cool, ambient, and basking zones)

• Placing UVB too far away or behind glass/plastic (it blocks UV)

💡 Pro Tips for Setup

• Use a UV index meter if you want to fine-tune placement

• Place UVB over mesh, not glass

• Combine a heat source + UVB over a basking area to replicate the sun

• Give your reptile hiding spots on both warm and cool ends

🦎 Final Thoughts

Lighting isn’t just about keeping your pet visible—it’s about giving them the tools they need to grow, eat, move, and thrive. Each type of light plays a specific role, and understanding how they work together is key to building a healthy, naturalistic environment.