To those familiar with bioactive enclosures, the first image that comes to mind is often a vibrant, tropical vivarium resembling the Amazon Rainforest. The moisture and humidity levels of a rainforest vivarium are conducive with keeping plants and the moisture-loving invertebrate clean-up crews, but arid bioactive enclosures are achievable also! In this section, we will go over the differences between arid and tropical bioactive enclosures, so you feel more confident in wanting to shift to bioactive for any reptile species you may own.

Animals that live in tropical environments have different humidity and moisture requirements than animals that live in arid environments. The key to setting up one environment over another in a bioactive enclosure is knowing the core components of a bioactive, then finding variants that suit each environment. Below, you will find a quick and easy chart that lays out a lot of core components and examples of each for arid and tropical environments.

Substrate

The drainage layer is the bottom layer. The drainage layer should be taller in accordance with how much humidity an environment needs. Tropical environments need more humidity which can be achieved by water evaporating, so having pooled water underneath your substrate allows for some leniency in how much water you add to the enclosure as part of regular maintenance. Drainage layers are also helpful for plants in tropical enclosures, as it aerates the roots and prevents root rot. Arid species often do better without a drainage layer, as drainage layers can cause excessive humidity. Because you will not be adding as much water to an arid enclosure, typically a drainage layer isn’t required. If you add a drainage layer, we recommend adding a layer of plastic mesh in between the base layer and drainage layer Excessive water in the drainage layer should be drained out if your humidity is too high, or to avoid flooding.

The leaf litter and moss layer is mostly the same in arid vs. tropical enclosures. Having a layer of leaf litter is necessary in all bioactive enclosures. The quantity and moisture level of the sphagnum moss, however, will definitely change. The higher your humidity requirement, the more sphagnum moss you should have in your enclosure. Sphagnum moss holds onto moisture very efficiently and is a great way to keep a stable humidity in the enclosure, because it will slowly leech out humidity over time. In arid enclosures, keep the moss slightly damp. In tropical enclosures, water it as needed and experiment with your humidity levels.

Next is the base substrate layer. Unlike the other two layers, the makeup of this layer will change instead of just how much of the layer there is. The base layer is the most important component to get right in a bioactive enclosure. This layer’s makeup is entirely dependent on your species’ husbandry needs, as some substrates hold more humidity, maintain stronger and more stable burrows, and support different plant species.

Arid Base Layer Substrate

Arid bioactive substrates are made of similar materials as tropical substrates, but the materials that make up the mixture are in different proportions. See the list below for some ideas on formulating an arid bioactive substrate.

A lot

• Play sand

• Organic topsoil

Some

• Coco coir

• Coco fiber

A Little

• Clay

• Reptile-safe wood chip material

• Charcoal

• Sphagnum moss (separate from the moss layer)