The researchers aimed to determine the best time for water treatment in a small-scale flocculation unit. They used a prototype with a 20 cm pipe diameter and tested different detention times on water from Kalimalang River. After analyzing the results, they found that the optimal detention time for water with 41-60 NTU turbidity is around 19.7 minutes. This means that the water is clearest and most purified after being treated for this specific amount of time.