A vivarium's whole climate can turn on one thing — how much water is trapped in the substrate at the bottom of it — which is what a compact expanding brick is actually for.

This is a natural terrain substrate compressed into a compact brick, 10x10x6cm dry, which Komodo say expands to seven times its size once soaked in water. Once expanded it is meant for woodland or rainforest-style vivariums, giving reptiles a loose, diggable substrate that Komodo say encourages natural burrowing behaviour.

• Compact brick, 10x10x6cm dry
• Expands to 7 times its size in water, per Komodo
• Natural substrate for woodland or rainforest vivarium setups
• Encourages natural burrowing behaviour, per Komodo
• Half-brick size

One thing worth knowing. No weight or volume figure is given for the expanded substrate, only the multiplier, so it is worth soaking a brick in a spare container first if the tank size is tight rather than assuming the maths works out exactly. No suitability by reptile species is specified beyond "woodland or rainforest habitats".

Who it's for: reptile keepers setting up or refreshing a woodland or rainforest-style vivarium who want a substrate that expands from a compact, easy-to-store block rather than buying loose substrate by the bag.