Feed is one of the important factors in aquaculture with a high enough content value for fish. So the need to formulate high-quality fish feed that suits the needs of fish increases. Lemna sp. is a water weed that can be used as an alternative ingredient for fish feed. This is because Lemna sp. has a high content of nutrients. A high crude fibre content in vegetable ingredients causes one of the obstacles to use as fish feed ingredients. However, this can be overcome by processing feed ingredients using the fermentation method. With the help of fermenter solutions, the fermentation process can produce simple combinations. This makes it easier to decompose than before. The fermentation procedure can affect the nutrient content of nutrients in Lemna sp. with flour and molasses and probiotics during the three-day incubation period is the best fermentation procedure. Fermentation is influenced by several factors, including the duration of incubation, number of inoculums, dose of probiotics, particle size, and pH.