How to Test Aquarium Water Temperature

Different types of fish need specific ranges of water temperature to survive. Fish that experience high or low temperature changes in an aquarium are susceptible to disease, illness and death. Maintaining the right temperature in an aquarium extends the fish's life.

Things You'll Need

  • Water thermometer
  • Aquarium
  • Aquarium light or heater
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Instructions

    • 1

      Purchase a water thermometer at a pet store or at a department store with a pet department. Aquarium thermometers clip or stick onto the side of the aquarium.

    • 2

      Determine the correct temperature the fish needs. A goldfish needs the water temperature to be between 40 and 90 degrees Fahrenheit. Beta fish require the temperature in the aquarium to be between 70 degrees and 85 degrees Fahrenheit. Most tropical survive in water between 72 and 78 degrees Fahrenheit. To find specifics about the temperatures tropical fish need, visit the Tropical Fish Data website.

    • 3

      Test the temperature of the water. Look at the aquarium thermometer to see what temperature the water is. If the water gets too hot, turn the light off or turn the heater down for one or two hours a day.

    • 4

      Check the water every day to look for any temperature changes. If the aquarium is too cold, keep the light turned on longer or turn the heater up. Continue to watch the temperature on a daily basis.