Koi, as eurythermal fish, their suitable water temperature needs to be dynamically adjusted according to different growth stages and seasons. Here are the key temperature ranges and management suggestions:
I. Core Temperature Ranges
Optimal growth water temperature: 20-25℃ (with vigorous metabolism, and the best performance in appetite and body color)
Survival limit range: 5-30℃ (can be tolerated for a short time, but long-term exposure to extreme temperatures will affect health)
Special needs during the breeding period: 24-28℃ (the highest embryo hatching rate, and the day-night temperature difference should be less than 1.5℃)
II. Key Points for Seasonal Management
High temperature in summer:
When the temperature exceeds 30℃, shading/aerating is needed to avoid floating heads caused by the decrease in dissolved oxygen.
32℃ is a dangerous critical point, which may cause heat stress.
Low temperature in winter:
Reduce feeding when the temperature is below 10℃, and stop feeding when it is below 5℃.
Ensure the stability of the underwater temperature when the water surface is frozen.
III. Precautions
Temperature difference sensitivity: A daily fluctuation of more than 2-3℃ can easily lead to stress or diseases.
Water quality coordination: Weakly alkaline (pH 7.0-7.5) and dissolved oxygen of 5-7mg/L are more conducive to temperature adaptation.
Mixed breeding risks: When mixed with tropical fish or Ranchu goldfish, the temperature requirements must be strictly matched.
It is recommended to maintain temperature stability through heating rods, shading equipment, and phased water changes.