Water dish
Keep a clean water dish available to Straight Horned Baboons once the spider is large enough to use one safely. Place it where it can be removed and refilled without dismantling the main retreat.
If a Straight Horned Baboon fills the dish with substrate or webbing, clean it and refill it. That behaviour is common and is not a reason to remove the dish permanently.
Substrate moisture
For Ceratogyrus marshalli, keep the enclosure mostly dry, with upper substrate with some lower moisture and clean water. Judge the substrate over several days instead of trying to keep every part equally wet.
Add water in controlled amounts for Straight Horned Baboons. The lower layers can remain moist longer than the surface, especially in deep or fossorial setups.
Ventilation
Moisture without enough airflow can leave a Ceratogyrus marshalli enclosure stale and persistently wet. Cross-ventilation helps moisture move through the enclosure instead of collecting as constant condensation.
If a Straight Horned Baboon enclosure smells sour, remains soaked or repeatedly grows mould across the surface, reduce water, improve airflow or both.
Slings and small enclosures
Small Straight Horned Baboons enclosures dry faster because they contain less substrate and air volume. Check them more frequently without turning that into constant disturbance.
For a tiny Ceratogyrus marshalli sling, use a suitably shallow water source when practical and keep the substrate appropriate for the species and life stage.
Around moulting
Keep water available when Ceratogyrus marshalli is in premoult and after the moult. Do not disturb the spider to make it drink; simply make sure access is there.
After a Straight Horned Baboon moults, leave the spider to harden. Hydration support means stable water access and suitable enclosure moisture, not spraying the animal directly.
Avoiding overwatering
More water is not automatically safer for Ceratogyrus marshalli. Persistently saturated substrate can create poor conditions even for species that appreciate a moisture reserve.
With Straight Horned Baboons, aim for the moisture pattern the species needs while still allowing ventilation and some normal drying. The water dish remains the constant source while substrate moisture is adjusted as required.