How to Test for Nitrates in Water With Light Waves

Molecular interactions such as those that occur through the nitrogen cycle are important for maintaining equilibrium in aquarium water. The reactivity of water is directly affected by the hydrogen bonding between water molecules. In an aquarium, products such as nitrates (N03-) from the fish's metabolic waste are continuously released into the water. Water, as universal solvent, bonds to these saturates and becomes overcrowded. As the distance between molecules decreases, the bond between water molecules and solute ions strengthens. It is possible to gauge the nitrates (NO3-) and other organics involved in this bond with the use of light waves from an immersion photometer.

Things You'll Need

  • 20 cc syringe
  • Nitrate test tube
  • Measuring spoon (supplied with test)
  • Nitrate test powder
  • Digital watch
  • Nitrate test tablet
  • Pipette
  • 25 cc graduation beaker
  • Nitrite LR tablet
  • Glass rod
  • Immersion photometer
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Instructions

    • 1

      Draw up 20 cc (4 teaspoons) of aquarium water with a syringe and deposit this into the nitrate (NO3-) test tube.

    • 2

      Add 1 level measuring spoon of nitrate (NO3-) test powder to the test tube. Seal the test tube with the cap supplied and shake the test tube vigorously for 60 seconds. The measuring spoon also comes with the test kit.

    • 3

      Open the test tube, taking care not to spill any of the contents. Place one nitrate (N03-) test tablet into the test tube and replace the cap. Shake the test tube vigorously for another minute. The tablet must dissolve completely. Shake the tube for longer than 60 seconds if the tablet has not dissolved by then.

    • 4

      Wait for the reducing agent to settle on the bottom of the test tube.

    • 5

      Invert the test tube a number of times to complete the flocculation process.

    • 6

      Place the test tube in a vertical position on one side for two minutes.

    • 7

      Use a pipette to carefully decant 10 cc (2 teaspoons) of the clear liquid resting above the sediment on the bottom of the tube into the 25 cc (5 teaspoons) graduated beaker. Decant only the clear liquid.

    • 8

      Add one nitrite (N02-) LR tablet to the graduated beaker. Gently crush this tablet with a glass rod. Stir thoroughly until the tablet is completely dissolved.

    • 9

      Wait 10 minutes and carefully immerse the sensor into the graduated beaker. Place the sensor to the very bottom of the beaker.

    • 10

      Read the measured value of nitrate.