The water temperature requirements for guppies need to be adjusted dynamically based on their growth stage and breeding needs. Here are comprehensive recommendations:
I. Daily Rearing Temperature
Adult fish: The optimal temperature range is 22–26°C (with 24°C being ideal). Within this range, they exhibit vibrant colors, high activity levels, and strong immunity.
Fry: A slightly higher temperature of 24–27°C is needed, which accelerates metabolism and growth. However, it should not exceed 28°C to avoid insufficient oxygen levels.
II. Temperature for Breeding Period
Breeding adults and hatching: The temperature needs to be raised to 26–28°C, with fluctuations kept ≤1°C. Sudden temperature changes can easily cause abnormal development of fish eggs or lead to adults refusing to eat.
III. Critical Temperatures and Risks
Low-temperature risks:
Appetite decreases when temperatures drop below 20°C, and death may occur below 15°C.
In winter, a heater is necessary to maintain temperatures above 20°C, preventing pseudo-hibernation or ich (white spot disease).
High-temperature risks:
Temperatures exceeding 30°C can cause oxygen depletion. Aeration equipment or cooling measures (such as fans) should be used accordingly.
IV. Seasonal Management Tips
Summer: Turn off the heater. Control temperatures via water circulation or ice packs to prevent exceeding 30°C.
Winter: Set the heater to a constant 24°C. When changing water, ensure the temperature difference between new and old water is ≤2°C.
V. Precautions
Prioritize stability: The daily temperature fluctuation should be controlled within 2°C; drastic changes can easily cause stress.
Equipment selection: For a 50-liter tank, a 100W heater is recommended, paired with a thermometer for real-time monitoring.