Koi fish to sleep while lying down. Fish rarely sleep lying down. Even some benthic fish will keep a normal swimming posture when sleeping, which means that they have lost their swim bladder. Swim bladder loss is one of the common diseases in fish. There are many reasons for this situation, which may be temporary or permanent. Temporary swim bladder loss is usually related to the change of feeding environment, which can be recovered by rest, but permanent swim bladder loss cannot be treated.

1. The temperature changes suddenly: If the water temperature is not well controlled when the seasons change, or the temperature of new water is not well controlled when changing water, it will cause a large temperature difference in water, which will stimulate koi fish and cause them to lie flat at the bottom of the tank. At this time, a heating rod should be used to adjust the water temperature to a similar degree to the old water. In addition, when changing water, you can add some hot water to make it similar to the temperature of old water. When changing seasons, the heating rod should be turned on as soon as possible, or covered with insulation film for insulation.

2. Scared: Strangers often walk up and down in front of the fish tank, or suddenly turn on the lights in the fish tank, which will scare the koi, causing the koi to lie flat at the bottom of the tank. If you want treatment, you need to put the fish tank in a quiet place to rest and wait for it to recover. When strangers approach koi, they should move lightly and the light should not be too strong.

3. Water quality deterioration: Unclean water quality, bacteria in fish tank, neglect of water management and irregular water change will lead to poor water quality. If you don't raise water well in fish farming, the constitution of koi will get worse, and it will also make koi easy to lie in a tank. At this time, the koi should be replaced with clean new water, then the water quality should be monitored in time, and the koi should be replaced with water regularly. The filter system can be installed if conditions permit.