Fish die for several reasons:
Reason one: support to death.
According to reports, a big habit of goldfish is gluttony. I don't know if it is broken, so we must strictly control the feeding amount. Especially when the weather is sultry, you can feed less.
Reason 2: Death due to inadaptability to water environment.
Once there are many bubbles around the fish tank, change the water immediately. Bubbles in the tank indicate that the water quality is not good, and fish will die easily if they don't change the water.
Reason 3: Not adapted to the smell in the water.
If the water smells of fish, change the water and disinfect the bathtub.
Reason 4: The fish in the fish tank died and was not disinfected afterwards, resulting in bacterial residues in the fish tank, and it is definitely impossible to continue to raise fish.