Leopard Gecko Thermostat Types Explained
| Recommended type | Pulse-proportional |
| Minimum acceptable | On/off thermostat |
| Never acceptable alone | Dimmer switch (no feedback) |
On/off thermostats
These switch the heat source fully on or off once a set temperature is crossed, which causes a temperature swing above and below the target. They're the cheaper, entry-level option and work adequately for many under-tank heater setups.
Pulse-proportional thermostats
These rapidly pulse power to the heat source in proportion to how far the temperature is from target, holding a much tighter, steadier range with far less overshoot. They're the current recommended standard, especially for overhead heat sources like halogens.
Dimmer switches are not thermostats
A dimmer switch only adjusts power output manually — it has no probe, no feedback loop, and no way to respond to changing conditions. Using one alone as your only temperature control is functionally the same as running a heat source unregulated.
Probe placement matters as much as the thermostat itself
Position the probe at the warm hide floor, not floating in open air or taped to the heat source itself, or the reading won't reflect what the gecko actually experiences.
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A single adult leopard gecko needs a 20-gallon long tank as an absolute minimum, with a 36x18 in (40-gallon breeder) footprint now considered the recommended standard — plus a secure lid, an under-tank heater on a thermostat, a thermal gradient, at least three hides, and a shallow water dish.
Set up in this order: substrate, then heat source wired through a thermostat, then hides and water dish, then decor — and run the whole enclosure for at least 24–48 hours to confirm stable temperatures before your gecko moves in.
Hatchlings can start in a 10-gallon tank or tub, juveniles do well in 20 gallons, and adults need a 20-gallon long as an absolute minimum — with 36x18 in (40-gallon breeder) now the widely recommended standard, not just an upgrade.
Heat a leopard gecko enclosure with an under-tank heater and/or overhead heat source (halogen or deep heat projector) wired through a thermostat — a thermostat is mandatory, not optional, and heat rocks should never be used.
Leopard geckos can survive without UVB using dietary D3 supplementation, but current husbandry guidance now recommends low-level UVB (roughly 2–6% T5) as best practice — it improves D3 synthesis, bone density, and natural behavior, and views on it have shifted significantly from older nocturnal-species advice.
Keep ambient humidity around 30–40% across most of the enclosure, with a dedicated humid hide raised to roughly 70–80% to support smooth, complete sheds.