A self-ballasted mercury vapour lamp that supplies heat, UVA and UVB from a single bulb — the usual choice for large terrariums and aviaries where running separate basking and UVB fixtures is impractical. It needs no external ballast, but it does need a ceramic socket in a vented or wire-cage fixture, and it cannot be run on a dimmer or a pulse-proportional thermostat. Output at close range is high, so this is not a lamp for a small enclosure.
Features
- Heat, UVA and UVB in one lamp — one fitting instead of two or three.
- Self-ballasted — fits a standard ceramic socket, no ballast required.
- Three wattages — 80W, 100W and 160W.
- Nickel-plated threads.
Fitting and positioning
Use a vented or wire-cage fixture — an enclosed dome traps heat around the lamp. Mount it at one end of the enclosure so the animal has a genuine thermal gradient to move along. For the 100W lamp, UV Index runs roughly 2.6–3.5+ at 13–20cm and 0.4–0.7 at 55–75cm; mesh screen cuts output 30–40%.
Replacement
Replace every 6 months. Like all UV lamps it will keep lighting and heating long after the UVB has gone.
A suitable fixture is the Wire Cage Clamp Lamp. More in Reptile Heating & Lighting.