# Setting Up a Terrarium: Basics of Heat, Light and Humidity

> A terrarium is a climate system with an animal inside. Understand temperature gradients, UVB, humidity and layout before buying.

- URL: https://nestjes.nl/en/knowledge-center/setting-up-a-terrarium-basics
- Category: Reptiles
- Published: 2026-06-28
- Author: Redactie Nestjes

A terrarium is not just a glass box. It must create the climate your reptile needs to digest, move, shed and stay healthy. Getting the environment right before the animal arrives is essential.

## Temperature gradient

Most reptiles need a warm area and a cooler area so they can regulate body temperature. Use reliable thermometers and a thermostat where appropriate. Guessing by hand is not accurate enough.

## Light and UVB

Many species need UVB to process calcium properly. The correct lamp, distance and replacement schedule matter. Other species may need less UVB but still benefit from a clear day-night rhythm.

## Humidity and layout

Humidity that is too low can cause shedding problems; too high can cause respiratory or skin issues. Provide hides, climbing or digging options according to the species. Run and measure the setup for several days before adding the animal.