Ponds are then cleaned of the plant debris. Harvested ling chiao are placed in large tubs where they are washed and further separated. Mature fruit, being somewhat heavier will sink, while the lighter, softer immature fruit float on the surface.
據當地菱農表示，水缸的作用有二：一方面讓農民將一袋袋剛採摘的菱角倒入洗淨，一方面也趁此機會將菱角分類﹘﹘成熟的菱角會沉至水底，幼嫩的則浮在水面。