Enclosure and maintenance
Adults reach about 17–20 cm (6.5–8 in). Grammostola grossa is a terrestrial species, so the enclosure should prioritise usable floor space, a snug ground-level retreat and enough substrate to keep fall height low.
With Grammostola grossa, routine care should not involve handling. Arrange the water dish, retreat and door so feeding and cleaning can be done without repeatedly disturbing the spider.
Growth, feeding and moulting
Growth is slow. Feed to the spider's size, appetite and abdomen rather than forcing a rigid weekly schedule; the routine will change as Grammostola grossa grows.
If Grammostola grossa refuses food and shows premoult signs, remove live prey, keep water available and leave it alone. There is no need to make a spider in normal premoult eat.
Lifespan and buying one
Guarani Giant females often live 20 years or more; males live roughly 4–6 years. For a female, that can be a decades-long commitment.
If a seller lists Guarani Giant as male or female, ask how that was confirmed. Also ask for an actual size in centimetres; sling, juvenile and sub-adult are too loose to plan the next enclosure around.