All the fish I used to take medicine died in the end. Later, after listening to the advice of fish friends, I changed all the water into dried water and added salt (that is, the salt of pickles, which is usually sold by fish), which is very cheap. It is very cheap to continuously add oxygen to the water, and some of them sell oxygen equipment (which is also sold by fish), which is beyond imagination. In this way, the fish will recover naturally for several days. The black or curly part of the edge of the fin indicates that the fish has been poisoned by some drugs. Repeated drug use used to kill more than a dozen people, but now it is more common. It must work my way. Now my fish occasionally has white spots. As long as I add oxygen and salt, I am already very confident. One reason is that the water is changed too frequently, and the other is that the water is too dirty. It is best to buy a small fish tank with filtering equipment to add oxygen and filter thoroughly, which is only twenty or thirty. Don't add too much salt. When salt enters water, it will be atomized. Put the right amount. If not, gradually increase. If it is too thick, the fish can't stand it. Besides, you have a hooded fish. If there are one or two white spots on the hat, it can be observed without wiping the cylinder or other abnormal phenomena, and sometimes the long hat will touch the white spots. It will be gone after a while. If you have white spots on your body, you must use the above method. In addition, be sure to dry the water before filtering. You can also wrap some cotton wool in thick gauze, sew it and throw it into a small jar, so that the water won't mix so fast and don't feed too much. Finally, I will buy a small filter pump to avoid getting sick.