To fertilize these two kinds of water, you must provide algae sources, and these are the dominant species. The water source must contain these two kinds of water, but in practice, everyone may not have the conditions. It is best to select and separate the dominant algae species from nature, inoculate them in the laboratory, cultivate them in the algae nutrient solution, then cultivate them in the algae culture pond, and then take water from the shrimp pond. Having good algae species is the first step. In the next step, the fertilizer water should have nutrients needed by algae species, among which nitrogen, phosphorus and silicon are essential for cultivating green algae water and diatom water. What kind of water you want to cultivate depends on their proportion. If the ratio of nitrogen to phosphorus is less than 4, cyanobacteria water can certainly be cultivated. If the ratio of nitrogen to phosphorus is 7, there is no problem with green algae water and diatom water. People will ask us if there is any way to detect the ratio of nitrogen to phosphorus in water and nitrogen to phosphorus in fertilizer. Isn't that a technical problem in production? Don't worry, I'll tell you the actual method. After all, our farming is not as accurate as scientific research, as long as we can successfully raise shrimps and prawns. It is necessary to introduce fertilizers and aquatic products here. It is safer not to use chemical fertilizers, especially fertilizers with high nitrogen content, urea, ammonium bicarbonate and so on. The ratio of nitrogen to phosphorus will definitely be out of balance in the pond.