1. Disinfect the fish tank thoroughly, mix it with potassium permanganate and tap water, soak it for 2 hours, and then wash it with clear water for later use. The color of potassium permanganate water can be adjusted to purple, but not to deep purple.

2. Interception of water: put tap water into a water interception container, and pump oxygen for 24 hours to allow chlorine gas to flow freely.

3. Put the disinfected fish tank into the filter, add the trapped water and let it stand for three to seven days.

The fish you just bought should be soaked in water. First, put the bought fish and plastic bags into the fish tank for 20 to 30 minutes, then continue to soak the plastic bags in the fish tank, and at the same time pour the water from the newly opened fish tank into the plastic bags filled with fish. After 20 minutes or half an hour, repeat the previous step three times, adding one third each time, at intervals of 20 minutes or half an hour, and then pour out the water in the plastic bag and put it in.

5. Rest for three days, do not feed, and change one-third of the water after releasing the fish for one week.