1, reason: Their bodies are easily infected by bacteria, because their resistance is still very poor. So if the water is not clean, they can get sick easily.

2. Treatment method: Change water in time and add proper amount of salt in fish tank. Change the water regularly every week, about one third of which can be changed every time. After that, a proper amount of salt should be added to the water to sterilize and disinfect.

1. Reason: They eat a lot, but when they eat too much food at one time, their abdomen will accumulate food, which leads to indigestion and does not like swimming.

2. Treatment: Stop feeding in time and input enough oxygen into the fish tank. When they have indigestion, they don't eat again. Therefore, it is necessary to stop feeding to prevent the food residue in the water from polluting the water quality, thus making the silver arowana sick and dead. Finally, putting enough oxygen into fish tanks can improve their metabolic ability.

1. Reason: When they are malnourished, they may not like to swim. Because there is no nutrition supply, their physique will be weaker.

2. Treatment: Feed a small amount of food several times and feed fresh live bait to enhance nutrition.