The reason why the fish in the fish tank always stay at the bottom may be due to the following reasons:

1. Water quality: It may be that the owner has not changed the water for a long time, causing the water quality to deteriorate, causing the fish to lie down in the tank.

2. Water temperature: It may be caused by the water temperature being too low or the water temperature dropping after changing the water.

3. The fish feels scared: It may be that the fish itself is timid and feels uneasy when seeing a black shadow shaking.

4. Stress response: There will be a certain amount of pressure when a new fish enters the tank or changes the water. When the fish is not used to it, it will lie at the bottom of the tank. It will get better after a while.

5. Sickness: If the fish has been raised for a period of time and suddenly stays at the bottom of the tank, it may be that the fish is sick and needs to be isolated and treated as soon as possible to avoid infecting other fish.

Tip:

When raising fish, you must strictly control the water temperature and quality, otherwise it may affect the survival of the fish. Change the water regularly to keep the water clean. If the breeding density is too high, the frequency of water changes will also increase. And it is best to install an oxygenating device.