For a species that lives on vertical surfaces, the floor of the enclosure does more work than it looks like. It stores the water that keeps the lower zone humid, it cushions a fall from the lid, and it hosts the clean-up crew that keeps mould down.
What to use
- Coco fibre on its own: cheap, holds water well, easy to rehydrate.
- Coco fibre with topsoil (peat-free, fertiliser-free): holds structure better and supports springtails.
- A handful of sphagnum moss pressed into one corner: a slow-release moisture reservoir.
Avoid vermiculite as a main substrate, avoid anything with added fertiliser, and avoid bark chips, which trap prey remains where you cannot reach them.
How deep
Four to six centimetres for an adult enclosure. Deep enough to hold a week of moisture and to soften a fall, shallow enough that the lower vent band still sits above it. In a T-LOVER enclosure the intake holes start six centimetres above the floor precisely so a five centimetre substrate layer never blocks them or wicks water into them.
How to water it
Pour along one back corner until the lower half darkens. Do not soak the whole surface: you want a wet zone and a dry zone so the spider can choose. Let the top lighten between waterings.
When to change it
Rarely. A substrate with springtails and no prey remains can run for a year or more. Replace it if it sours, if you see persistent mould after fixing the ventilation, or if a mite bloom takes hold. Otherwise, top up rather than strip out: a full substrate change destroys the web anchoring the spider has built at the base.