When Do Goldfish Spawn? A Detailed Guide to Spawning Time and Seasons

Goldfish are a common ornamental fish in daily life, and because they look attractive and are easy to keep, they are deeply loved by fish keepers. Many people like to keep a few at home, so when do goldfish spawn?

1. When do goldfish spawn?

Goldfish generally spawn in the morning after a rainy or foggy day when the temperature is above 16 degrees. However, spawning is best at around 20 degrees, and the approximate time is from early morning to around 9 a.m. Changing to new water can also promote spawning. In addition, if the male fish keeps chasing the female fish and sometimes even knocks the female fish over, that indicates spawning is about to happen.

2. What should be noted during the goldfish spawning period?

(1) Water temperature requirements

The length of time for goldfish eggs to hatch changes with the water temperature. Generally, it takes 3-7 days from the eggs being laid to the hatching of small fish. If the average water temperature is 15-20°C, the hatching period is 5-7 days; if the average water temperature is 20°C, small fish can hatch in 4-5 days; if the average water temperature is 20-25°C, only 2-3 days are needed. In short, the lower the water temperature, the longer the hatching time.

The water temperature in the hatching pond should be kept at around 20°C, preferably not lower than 16°C, and at most not higher than around 28°C. The temperature difference fluctuation should preferably not exceed 6°C, and at most not exceed 10°C, otherwise it can easily cause the death of colored eggs or increase the number of deformed fry.

(2) Weather effects

Generally, during the first spawning of each year, the air temperature and water temperature tend to be on the low side. If there is also alternating cold and hot weather and rainy days, some eggs may be delayed to about 10 days before small fish hatch, and the coloration rate and the rate of quality fry are also low (except when artificial heating is used). In June-July, when the water temperature reaches around 28°C, small fish can hatch in about 2 days.

Practice has shown that when the water temperature is changeable, or too low or too high, even if small fish can hatch, the rate of quality fry will be affected. However, small fish hatched at around 18°C over 5-7 days have better constitution and a higher rate of quality fry.

(3) Effect of water pH

The pH of the water in the hatching pond is required to be around 7.5, preferably not higher than 8, and at minimum not lower than 7.2. Special attention should be paid to keeping enough dissolved oxygen in the water in the hatching pond. If conditions permit, an oxygen pump should be installed, but the intensity of aeration should be gentle and weak. It should not be too strong, so as to avoid excessive movement of the water in the pond (tank), which would affect the development of fish eggs and fry.

Overall, when the temperature reaches above 16 degrees, goldfish may spawn. During spawning, it is essential to control the water temperature, water quality, and weather changes well.