Pour 1/2 jar marinara sauce in a slow cooker
Add grated zucchini, ground turkey, dry white rice and bread crumbs in a bowl. Mix well.
Add a generous pinch of salt (if you like your food a little saltier).
Use a cookie scoop to form even 1.5 tablespoon sized meatballs (or form with your hands) and place balls in the slow cooker.
Pour remaining 1/2 jar of marinara sauce over meatballs.
Cook on high for 4 hours