How to Check Copper in a Saltwater Tank

Copper is often added to saltwater tanks to inhibit or cure parasite infections. However, high levels of copper may be unsafe for some fish and can also be toxic to other species living in a saltwater aquarium. By monitoring copper levels closely, you will keep your saltwater tank as safe as possible for its inhabitants. Aquarium supply stores sell kits that can be used to test the copper level in salt water. You should use one of these kits, rather than trying to create a do-it-yourself kit, because the chemical reactions involved are complex and can sometimes be dangerous.

Things You'll Need

  • Salt water copper testing kit, which will include:
  • Eyedropper
  • Test tube
  • Salt water copper test solution
  • Color chart for test solution
  • Testing instructions
  • Test tube cap
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Instructions

    • 1

      Use the eye dropper to take a sample of the salt water and add it to the test tube until the measurement mark is reached. Each brand of copper test kits requires that a different amount of water be tested, so do not use a test tube from an old test kit to measure copper levels with new testing solution.

    • 2

      Add the required number of drops of the testing solution to the test tube. To ensure the most accurate measurement, hold the bottle vertically above the test tube, rather than holding it at an angle. Do not let the testing solution come in contact with the water in the tank or with your skin, as it is usually strongly acidic or basic.

    • 3

      Cap the tube and shake well. Let the test solution react with the water for the amount of time required by the instructions. This may vary from 60 seconds to more than 20 minutes, depending on the brand of the test solution.

    • 4

      Compare the color of the water to the colors on the testing chart. The level indicated will be in parts per million.

    • 5

      Test the copper level frequently if you are adding copper to your saltwater tank. This is important because excess copper can kill your fish, but removing excess copper involves partially emptying and refilling the tank.