Fish don't eat because the temperature is too low. As a temperature-changing animal, its adaptability to temperature is weak, and low temperature will affect its appetite. If it is tropical fish, the water temperature should generally be controlled above 20 ℃, and heating rods should be installed in the fish tank to control the water temperature. If it is a wide-temperature fish, the water temperature should not be too low, preferably around 15 ℃.

Poor water quality also has a great impact on fish, which will also cause it not to eat. If the water quality deteriorates seriously, it will not only make it lose its appetite, but also endanger its health. Usually, in order to maintain the water quality, filters need to be installed in the fish tank, and water needs to be changed regularly to improve the water condition, so as to ensure the health of fish.

Fish also has taste. If food is not delicious, it will not be eaten. According to the different feeding habits of fish, the food choices are also different. If it is herbivorous fish, it can be fed with aquatic plants or algae, while carnivorous fish should use animal feed such as small fish and shrimp. Omnivorous fish can eat a lot of things, and usually choose fish food.

If the fish eats too much in the last meal and the feeding interval is short, the fish may not eat. In this case, don't continue feeding, because if you don't eat it, it will also lead to a large number of microorganisms and an increase in ammonia nitrogen content, which will accelerate the deterioration of water body and be harmful to the health of fish.