Shows whether your UVB bulb is still producing UV output.
UVB Test Card – Reptile Light Checker
Place it under any UVB lamp and it turns purple if the bulb is still working — no meters or guesswork needed to check your lighting.
UVB bulbs lose output before they burn out — this card tells you when it is time to replace yours before your reptile is affected.
Hold the card under your reptile lamp for a few seconds — if the sensor strip turns purple your bulb is still producing UVB output. If it stays the same color or reacts weakly, the bulb has degraded and needs to be replaced. That is the entire process. No apps, no meters, no settings to adjust. The card detects both UVA and UVB so you get a read on the full UV spectrum your bulb is putting out rather than just one part of it. Works with fluorescent UV tubes, compact coil bulbs, and mercury vapor bulbs — the most common types used in reptile keeping.
This card solves one of the most common and most overlooked problems in reptile care. UVB bulbs do not burn out the way regular light bulbs do — they keep producing visible white light long after the UV output has dropped to a level that is no longer useful for your animal. Most keepers have no way of knowing this has happened and continue running a bulb that looks fine but is no longer doing its job. For reptiles that depend on UVB to synthesize vitamin D3 and process calcium — bearded dragons, tortoises, chameleons, and aquatic turtles especially — a failed bulb can lead to metabolic bone disease over months without any obvious warning signs until the damage is done.
Most UVB bulbs should be replaced every six to twelve months regardless of how they look. Use this card at installation to confirm your new bulb is working, then check again at the six month mark to see how the output has changed. Store the card away from direct light when not in use to preserve the sensor. Works with all standard reptile UV lamps across desert, tropical, and aquatic turtle setups.