Things You'll Need
- Tank cover
Instructions
Turn down your tank heater to maintain the water temperature at the lower end of the appropriate temperature range for your fish. The warmer the water, the more it will evaporate. For example, freshwater angelfish need water temperatures in the range of 75 to 82 degrees Fahrenheit. Keep the temperature closer to 75 degrees to prevent evaporation.
Use a cover for your fish tank that encloses the top completely. This way, any evaporated water will condense on the cover and fall back into the tank.
Turn the light off at night. The tank light also heats the water and increases evaporation rates.