What the substrate needs to do
Use a clean soil-style substrate for Chromatopelma cyaneopubescens that can hold its shape without becoming hard, dusty or permanently waterlogged.
For Chromatopelma cyaneopubescens, the substrate in a Green Bottle Blue enclosure should support normal movement and retreat building. Heavy decor must not be able to collapse if the spider digs underneath it.
Depth
Green Bottle Blues are terrestrial, so give Chromatopelma cyaneopubescens enough substrate for normal digging while also keeping the fall distance from the lid low. A stable ground-level hide should sit securely on or in the substrate.
Match substrate depth to the current size of Chromatopelma cyaneopubescens. Small slings and fossorial individuals often use proportionally more depth than a large settled terrestrial adult.
Moisture
For Green Bottle Blues, use a mostly dry, well-ventilated setup with a water dish; slings appreciate a small damp area rather than a wet enclosure. Add water in a controlled area and judge how the enclosure changes over several days instead of trying to keep every centimetre equally wet.
Substrate moisture for Chromatopelma cyaneopubescens should work together with ventilation. Persistent condensation, a stale smell or widespread mould usually means the setup is staying too wet.
Compaction and stability
Press the lower substrate layers firmly enough that a retreat or burrow for Chromatopelma cyaneopubescens does not collapse immediately. The upper surface can remain looser where appropriate.
For Chromatopelma cyaneopubescens, keep rocks, heavy cork and ornaments in a Green Bottle Blue enclosure low and secure so excavation cannot undermine them.
When substrate needs replacing
Spot-clean waste and prey remains from the Chromatopelma cyaneopubescens enclosure. Normal digging, webbing or rearrangement by the spider is not a reason to replace clean substrate.
For Chromatopelma cyaneopubescens, replace all substrate for a Green Bottle Blue only when it is fouled, contaminated, persistently mouldy or no longer structurally usable.