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Water quality

The Open Colorimeter is a very useful tool when it comes to water quality measurements. Instead of attempting to visually match a test strip to a colour chart, you can just insert the sample into the colorimeter and it will give you an exact result. This is great for community science projects that want to accurately report their data.

API makes a series of test kits that can be used with the Open Colorimeter. API kits are widely available in aquarium stores, so should be relatively easy to obtain in store or online.

Ammonia

The Open Colorimeter comes pre-calibrated for the API ammonia test kit:

Ammonia selection on Open Colorimeter

Equipment needed

  • Colorimeter with 630nm LED board
  • Two cuvettes
  • API ammonia test kit with two test tubes
  • Distilled water

Method

  • Take two test tubes with caps form the API kit
  • Fill (up to the 5mL line) one tube with distilled water (tube A) and the other with the water sample (tube B)
  • Add 8 drops of API Ammonia Test Solution #1 to each tube, holding the dropper completely upside down to ensure that the drops are the same size
  • Add 8 drops of API Ammonia Test Solution #2 to each tube, holding the dropper completely upside down to ensure that the drops are the same size
  • Cap the test tubes and shake vigorously for 5 seconds
  • Wait 5 minutes for the colour to develop
  • Pour some of tube A into one cuvette (cuvette A), and some of tube B in the test tube into the other cuvette (cuvvette B)
  • Turn the colorimeter on, press the top left button for the main menu. Select test 3 - Ammonia API (630)
  • The screen should display Ammonia API 0.00 ppm and not blanked
  • Place cuvette A (distilled water) into the colorimeter, and press the top right button to start the blanking process
  • When the blanking process is complete, remove cuvette A and insert cuvette B (water sample)
  • The ammonia concentration will be displayed in ppm (parts per million)

Here is a video from IO Rodeo that displays the process: