When the excrement from the top layer of fish seeps down to the middle layer, it acts as an "organic farm" producing algae that keep the shrimp well fed.
有鱗魚類的排泄物滲入下層後，成了培養藻類的「有機農園」，可以讓蝦子吃得飽飽的，有助於蝦類成長。