1. Reasons for water quality: If it is determined to be the cause of water quality, the water should be changed as soon as possible, and good water quality must be maintained.

Second, the feeding method is wrong: if you feed the seven-star saury to eat too much food at one time, it will cause them to be difficult to digest and not eat. So we must be quantitative when feeding.

Three, the cause of the disease: the most likely disease is the internal The external manifestation of such a disease is not obvious. If it is determined to be internal, you can use a drug such as Trichlorfon or Trichlor, and a certain dose according to the size of your fish tank and the condition of the seven-star saury.