In a large soup pot, bring the stock and water to a boil.
Reduce the heat to a simmer, then add the meatballs.
Cook the meatballs for 20 minutes, stirring occasionally.
Add the potatoes, salt, pepper, cumin, coriander, and paprika. Simmer for 10 minutes
Add the zucchini, and simmer for an additional 15 minutes.
When ready to serve, stir in the fresh lime juice.