Slings
Young Entre Rios Tarantulas usually eat more regularly because they are growing and moulting more often. Offer small prey to Grammostola iheringi in sensible portions and remove leftovers before they spoil.
If an Entre Rios Tarantula sling suddenly stops eating, premoult is one common explanation. Keep water available and do not keep adding live prey.
Juveniles
Juvenile Grammostola iheringi can normally take larger meals than slings, but the interval should still follow body condition rather than a fixed weekly rule.
If the abdomen of an Entre Rios Tarantula already looks very full, wait before feeding again. More food is not automatically better husbandry.
Adults
Adult Grammostola iheringi can go much longer between meals than fast-growing slings. Offer suitable prey, then let appetite and abdomen condition guide the next feed.
A large adult Entre Rios Tarantula does not need to eat simply because seven days have passed. A healthy tarantula can tolerate gaps that would be unusual for a mammal.
Premoult and fasting
When Grammostola iheringi appears to be in premoult, remove live feeders and stop offering more until after the moult and hardening period.
Food refusal in Entre Rios Tarantulas can also follow a rehouse or occur with mature males. Check the whole context before changing prey or feeding more often.
Simple records
Record feeds, refusals and moult dates for Grammostola iheringi if you keep several spiders. A short note is enough to show whether a long fast is unusual for that individual.
Those dates are more useful for an Entre Rios Tarantula than forcing every spider onto the same feeding calendar.