Warm End, Cool End: Setting Up Your First Leopard Gecko Vivarium

Leopard geckos are famously easygoing, which is exactly why they get set up badly. They tolerate a lot before they complain. But a gecko who is slightly too cool for months doesn't digest properly, and a gecko with nowhere humid to shed ends up with dead skin stuck round her toes.

The good news: once the heat and the hides are right, the rest is mostly tidying. Here's how to build it properly the first time.

Start with the box

Forget the old 60cm starter kits. For one adult leopard gecko, aim for a minimum of 90cm long by 45cm deep, and 45cm tall gives you room for low climbing and overhead heating. Bigger is genuinely better — a 120cm vivarium lets you build a proper gradient rather than a warm half and a slightly-less-warm half.

Wooden vivariums hold heat and are easy to heat from above. Glass terrariums look lovely and ventilate well, but lose warmth faster, so they need a warmer room or a bit more wattage. Either works. What matters is that it's escape-proof, well ventilated, and long enough that one end can be genuinely cool.

House her alone. Leopard geckos are not social, and keeping two together — especially two males, or a mismatched pair — leads to bullying, bitten tails and one animal quietly getting the worse spot.

The temperatures she needs

Leopard geckos take most of their heat through their belly, from warm surfaces, which is why floor temperature matters more than the air temperature halfway up the tank.

Target figures, measured at the substrate surface:

• Warm basking surface: 32–35°C, and never above about 36°C
• Inside the warm hide, at floor level: around 30–32°C
• Cool end: 22–25°C
• Night-time: a drop to roughly 18–21°C is normal and healthy

How you produce that heat is where keepers differ, and honestly both camps have a point. Heat mats under one third of the floor are the traditional route and replicate belly heat from sun-warmed rock. Overhead heating — a low-wattage halogen spot by day, or a deep heat projector or ceramic emitter for gentle round-the-clock warmth — better mimics sun from above and warms the air as well as the ground. Many modern setups use overhead heat with a mat as a backup in a cold room.

Whatever you choose: a heat source that isn't on a thermostat is a burn waiting to happen. Mats need a basic on/off mat stat. Halogen bulbs need a dimming thermostat. Ceramics and deep heat projectors run on a dimming or pulse stat. This is the one bit of kit you don't economise on.

Get the gradient right and everything else gets easier. Get it wrong and nothing else quite works.

Measure it properly

The stick-on dial thermometers that come in starter kits are close to useless. Buy a digital thermometer with a probe and tape the probe to the floor at the warm end, inside or just beside the warm hide — not on the back wall. A cheap infrared temperature gun is the other great purchase: point, click, and you can read the basking surface, the cool end and the hide roof in ten seconds.

Set the whole thing up and run it for three to five days before she moves in. Adjust. Watch it overnight. A vivarium that's perfect at 7pm can be 17°C by 4am if the room drops.

Light, UVB and day length

Leopard geckos are crepuscular — most active at dawn and dusk — and they were long kept without UVB, relying on vitamin D3 in their supplements. That still works. But the evidence has shifted, and low-level UVB is now widely recommended as beneficial: it supports natural D3 production and seems to encourage more natural behaviour.

If you add it, use a low-output tube suited to shade-dwelling species (Ferguson Zone 1), mounted over the warm end, covering roughly a third to a half of the enclosure, with hides underneath so she can always get away from it. Run lights on a timer for about 12 hours a day, shorter in winter if you like. Replace UV tubes on the manufacturer's schedule — they stop emitting useful UV long before they stop glowing.

Floor, hides and the one that saves her shed

Substrate is the internet's favourite argument. Safe, simple options: textured ceramic tile, lino, or plain kitchen roll for a new or unwell gecko. A bioactive-style mix of topsoil and play sand suits an adult in good health and lets her dig, which they clearly enjoy. Avoid calcium sand and crushed walnut shell entirely — both are associated with impaction and are not worth the risk.

She needs three hides, all snug enough that her back touches the roof:

1. A warm hide on the heated end, where she digests.
2. A cool hide at the far end, for when she's had enough.
3. A humid hide in the middle or warm-ish zone — a tub with an entrance hole, packed with damp sphagnum moss or kitchen roll, re-dampened every couple of days.

That humid hide is the difference between a clean shed and stuck skin round her eyelids and toe tips. Ambient humidity in the rest of the vivarium can sit comfortably around 30–40%. Add a shallow water bowl at the cool end, changed daily, and clutter the floor with cork bark, flat rocks and low branches. A gecko with hiding places out in the open is a gecko you'll actually see.

The first fortnight

Let her settle. Move her in, leave the lid shut, and for the first week do nothing but change water and offer food. New geckos often refuse to eat for several days — that's normal while temperatures are correct and she's otherwise bright.

Feed appropriately sized live insects: brown crickets, dubia roaches, black soldier fly larvae, with waxworms as an occasional treat. Dust with a plain calcium supplement at most feeds, and a multivitamin with D3 once or twice a week, following the product's instructions — supplement brands vary, so read yours rather than copying a forum schedule.

After a week or so, start short handling sessions: a few minutes, low over a sofa or your lap, ending while she's still calm. Weigh her weekly on kitchen scales and write it down. A fat, carrot-shaped tail and a steady weight tell you the setup is working better than any amount of guesswork.