A bioactive vivarium UVB guide helps you set up the correct lighting for both your reptile and live plants. Different reptile species have dramatically different UVB needs based on their natural sun exposure (Ferguson Zone). Select your species to get specific UVB requirements, photoperiod, and plant light compatibility for your setup.
Select Your Species
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Recommended Bulbs
Plant Light Compatibility
Ferguson Zone Reference
| Zone | Description | Target UVI | Example Species |
|---|---|---|---|
| Zone 1 | Shade dwellers | 0–0.7 | Dart frogs, Crested geckos |
| Zone 2 | Partial shade | 0.7–1.0 | Ball pythons, some skinks |
| Zone 3 | Partial sun | 1.0–2.9 | Bearded dragons, chameleons |
| Zone 4 | Full sun baskers | 2.9–7.4+ | Tegus, Sulcata tortoises |
How to Set Up Bioactive Vivarium UVB Lighting
Proper UVB lighting is critical for reptile health — UV radiation enables reptiles to synthesize vitamin D3, which is essential for calcium metabolism and bone density. In a bioactive vivarium, you also need to balance UVB output with plant growth light requirements, which operate in different spectra.
Understanding the Ferguson Zones
Dr. Gary Ferguson's research categorized reptiles into four zones based on their natural basking behavior. Zone 1 species (dart frogs, crested geckos) live in forest shade and need minimal UVB. Zone 4 species (tegus, sulcata tortoises) bask in full tropical or desert sun and need intense, long-duration UVB exposure.
Combining UVB and Plant Lights
For a bioactive vivarium, you typically run two light types: a UVB tube (T5 HO or LED UVB) for reptile health, and a separate LED grow light or T5 grow tube for plant growth. The UVB tube provides the narrow UV-B spectrum (280–315nm), while the grow light provides the PAR spectrum (400–700nm) that plants photosynthesize. Low-light plants like pothos, ferns, and certain bromeliads can thrive under T5 HO UVB alone.
Setting Up the UVB Gradient
A proper UVB setup creates a gradient — highest UVI at the basking spot, tapering to near-zero in shaded hides. This allows the reptile to self-regulate UV exposure. Position your basking spot directly under the UVB fixture at the manufacturer's recommended distance. Provide dense foliage or cork bark hides at the far end of the enclosure so the animal can retreat from UV entirely.
Frequently Asked Questions
Is this vivarium UVB lighting guide free?
Yes, completely free with no signup required. All reference data is built into the page and runs entirely in your browser.
Is my data private when using this tool?
Absolutely. Everything runs locally in your browser. No settings or interactions are transmitted anywhere.
What is a Ferguson Zone?
Ferguson Zones (1–4) categorize reptiles by their natural sun exposure behavior. Zone 1 species (shade dwellers like dart frogs) need very little UVB. Zone 4 species (full-sun baskers like tegus) need intense UVB. The zones were developed by Dr. Gary Ferguson and are the modern standard for reptile UVB recommendations.
Do bioactive vivariums need different lighting than standard enclosures?
Yes. Bioactive setups add live plants to the equation. Plants need appropriate light intensity and spectrum (often 5,000–6,500K white LEDs or T5 HO grow lights). You need to balance UVB output for the reptile with PAR (photosynthetically active radiation) for the plants. This guide covers both requirements.
Can I use a single T5 HO UVB bulb for both plant and reptile lighting?
Partially. High-output UVB T5 bulbs (like Arcadia 6% or 12%) provide some light for low-light plants like pothos, ferns, and bromeliads. For higher-light plants or full-spectrum setups, you need to supplement with a dedicated plant light (LED or T5 grow light) alongside your UVB fixture.
How far from the basking spot should the UVB bulb be?
UVI (UV Index) drops rapidly with distance. Most T5 HO UVB bulbs produce the target UVI at 8–12 inches from the bulb. The exact distance depends on bulb brand and output percentage. Always check the manufacturer's distance chart for your specific bulb model.