What the substrate needs to do
Use a clean soil-style substrate for Neoholothele incei that can hold its shape without becoming hard, dusty or permanently waterlogged.
For Neoholothele incei, the substrate in a Trinidad Olive Tarantula enclosure should support normal movement and retreat building. Heavy decor must not be able to collapse if the spider digs underneath it.
Depth
Trinidad Olive Tarantulas are fossorial, so give Neoholothele incei deep, compactable substrate that can hold a burrow. Depth is part of the enclosure design, not an optional extra.
Match substrate depth to the current size of Neoholothele incei. Small slings and fossorial individuals often use proportionally more depth than a large settled terrestrial adult.
Moisture
For Trinidad Olive Tarantulas, use slightly moist lower substrate with good ventilation; avoid waterlogged conditions. 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 Neoholothele incei 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 Neoholothele incei does not collapse immediately. The upper surface can remain looser where appropriate.
For Neoholothele incei, keep rocks, heavy cork and ornaments in a Trinidad Olive Tarantula enclosure low and secure so excavation cannot undermine them.
When substrate needs replacing
Spot-clean waste and prey remains from the Neoholothele incei enclosure. Normal digging, webbing or rearrangement by the spider is not a reason to replace clean substrate.
For Neoholothele incei, replace all substrate for a Trinidad Olive Tarantula only when it is fouled, contaminated, persistently mouldy or no longer structurally usable.