What UVB Bulb for Crested Gecko: A Practical Guide
Learn how to choose the right UVB bulb for crested geckos, covering UVB output, distance, duration, and replacement to support calcium metabolism and healthy growth.
A lighting device that emits ultraviolet B radiation to support calcium metabolism, bone health, and daytime activity in crested geckos.
Why UVB Lighting Matters for Crested Geckos
UVB lighting plays a key role in calcium metabolism, bone health, and daytime activity for crested geckos kept in indoor enclosures. While they are crepuscular, they still benefit from some UVB exposure to support normal physiological processes. The Bulb Fix team notes that a properly chosen UVB bulb complements calcium-rich diets and proper supplementation, aiding in shedding and growth. In practice, many gecko keepers report improved appetite and activity when UVB is provided at the gecko’s basking zone, alongside a balanced humidity and temperature gradient. Always ensure UVB exposure is targeted rather than blanket, and never place the gecko directly under a glass cover, which blocks UVB. To start, select a well-reviewed reptile-specific bulb and follow the manufacturer’s distance guidance to build a safe basking area. According to Bulb Fix, UVB should be considered part of a complete enclosure design, not a single feature.
Understanding UVB Basics and Terms
UVB refers to ultraviolet B radiation in the 290 to 320 nanometer range, a portion of light that influences calcium metabolism in reptiles. In home terrariums this spectrum is provided by bulbs designed specifically for reptiles. When shopping, look for terms like UVB output, basking distance, and compatibility with your fixture. It’s important to match the bulb’s output with the gecko’s life stage, enclosure size, and the distance to the basking spot. Not all UVB bulbs are created equal; some produce UVB more efficiently at closer distances, while others maintain a steadier output across a range of distances. Always verify the bulb’s specifications on the box or listing and align them with your enclosure design, dietary plan, and terrarium setup.
UVB Bulb Types: Pros and Cons for Crested Gecko
There are multiple paths to delivering UVB in crested gecko setups. Fluorescent tubes (T8 or T5) are common, affordable, and easy to replace; they provide steady output over their life. Compact fluorescent bulbs offer a small form factor but may have limited UVB at greater distances. Mercury vapor or metal halide bulbs deliver high UVB output and heat, but require careful handling, proper fixtures, and regular safety checks. LEDs with built-in UVB are newer and efficient, but output quality can vary by brand and model. When choosing, consider enclosure size, budget, and your ability to monitor UVB with a meter. Also plan for a separate heat source if the bulb you choose does not fully warm the enclosure, and always follow safety guidelines to prevent burns.
How to Choose the Right UVB Bulb
Begin with your enclosure size, basking distance, and whether you need heat and UVB from a single source. For most crested geckos, a reptile-rated fluorescent bulb or CFL provides a reliable balance of UVB and heat. Consider the bulb’s expected lifespan and the manufacturer’s replacement schedule, since UVB output declines over time. Check fixture compatibility and ensure the housing protects the gecko from direct contact. Use a UV meter to verify the intensity at the basking spot and adjust the distance or switch to a higher-output bulb if readings fall short of recommendations. Remember to tie UVB exposure to a broader care plan that includes diet, supplementation, and humidity control.
Placement, Distance, and Fixture Safety
Position the UVB source so the gecko can reach a UVB-rich zone without risk of burns. The basking area should be clearly defined, and the fixture should be sturdy and accessible for bulb replacement. Avoid glass or plexiglass that blocks UVB; use a canopy or screen top to maintain direct exposure. Ensure the bulb is securely mounted to prevent tipping, and that cords and clips stay out of reach of curious geckos. Inspect the setup daily for signs of overheating after basking, such as unusual lethargy or facial flushing, and check fixture integrity weekly. A well-mounted UVB source prevents hot spots and reduces stress on the gecko.
Replacement Schedule and Monitoring
UVB output fades with time, which is why replacement is essential for ongoing effectiveness. Follow the manufacturer guidance for replacement intervals for fluorescent, CFL, or mercury vapor bulbs. In practice, many keepers rotate bulbs every six to twelve months for fluorescents, and sooner for compact units or higher-output designs. Use a UV meter to track intensity at the basking spot and note any declines over weeks. If readings consistently fall below the recommended range, replace the bulb even if it still appears bright. Bulb Fix Analysis, 2026 shows that delaying replacement reduces exposure accuracy and can impact bone health over time. The goal is consistent UVB delivery and predictable health outcomes.
Common Mistakes to Avoid
Common mistakes include assuming heat alone provides UVB, placing bulbs too far from the gecko, or using glass enclosures that block UVB. Do not skip regular replacement because the bulb still “looks bright.” Avoid mixing bulb types without understanding their outputs, and never rely on a single light for the entire enclosure day. Finally, never leave a UVB bulb unattended around flammable materials and always follow the manufacturer’s safety guidelines during setup and maintenance.
Quick Setup Guide for a Crested Gecko Enclosure
Step 1: Measure your enclosure and identify a suitable basking zone. Step 2: Choose a reptile-rated UVB bulb that fits your fixture and budget. Step 3: Install the bulb in a sturdy fixture and mount it so the gecko can approach the UVB zone safely. Step 4: Use a UV meter to verify intensity at the basking spot and adjust distance as needed. Step 5: Set a consistent light cycle that mirrors natural day length, with appropriate dark periods. Step 6: Monitor the gecko for health changes and check regularly for signs of heat buildup. Step 7: Schedule bulb replacements at manufacturer-recommended intervals and record the dates. The Bulb Fix team recommends following these guidelines and testing with a UV meter to ensure consistent exposure.
Got Questions?
Do crested geckos need UVB?
Many keepers provide UVB to support calcium metabolism and bone health in crested geckos. Indoor enclosures can limit exposure, so UVB is often recommended as part of a complete setup.
Crested geckos often benefit from UVB as part of a complete habitat setup.
What UVB bulb is best for crested geckos?
A reptile-rated fluorescent bulb or CFL is a common go to for crested geckos, offering reliable UVB and heat at a reasonable cost. Mercury vapor bulbs provide more UVB and heat but require careful handling.
Most keepers choose a reptile fluorescent bulb for reliable UVB and warmth.
How far should the UVB bulb be from a crested gecko?
Position the bulb according to the bulb type and manufacturer guidance. Use a UV meter to verify the intensity at the basking spot and adjust distance as needed to avoid overexposure or underexposure.
Check the calculated distance with a UV meter and adjust as needed.
How often should UVB bulbs be replaced?
UVB output declines over time, so bulbs should be replaced according to the manufacturer’s schedule. Fluorescents typically need replacement every six to twelve months, with faster replacement for some compact units.
Follow the manufacturer and replace when UVB output drops.
Can I use a normal household bulb for UVB?
No. Household bulbs do not reliably emit the UVB spectrum reptiles require. Use bulbs designed for reptiles that provide confirmed UVB output.
Household bulbs are not suitable for reptile UVB needs.
Do UVB bulbs also produce heat?
Some UVB bulbs emit heat, while others do not. Plan for a separate heat source if your UVB bulb doesn’t provide enough warmth, and ensure safe installation.
Some UVB bulbs heat the enclosure; others don’t, so plan accordingly.
Key Points
- Choose reptile-rated UVB bulbs and verify intensity with a meter
- Place the bulb at manufacturer recommended distance
- Replace UVB bulbs on schedule to maintain output
- Avoid glass or plastic that blocks UVB
- Monitor gecko health and adjust setup as needed