How to Test in Biology for How Much Nitrates Are in Water

People who own wells should periodically test for nitrates in their water.

There are two forms of nitrates: NO3 (nitrate) and NO3-N (nitrate-nitrogen). High levels of nitrates are dangerous to humans and animals, even though NO3 is found in soil naturally and is necessary for life. High levels of nitrates can cause algae blooms in water bodies, depriving fish of oxygen. Because nitrates have no color, odor or taste, you must perform a chemical test to determine if a water source contains high levels of them.

Things You'll Need

• Latex gloves
• Litmus test strips
• Clean container

Instructions

1. Let the water flow for about three minutes if you are testing water from a pump or faucet.

2. Put on latex gloves. This will ensure that you don't contaminate the sample or get your hands dirty if you are drawing the sample from an outside source, such as a pond.

3. Make sure the container you are using to collect the sample is extremely clean, then rinse it several times with the water you will be testing.

4. Fill the sample container with water from the source.

5. Remove your gloves. Make sure your hands are completely dry.

6. Take a nitrate test strip out of the bottle, and close the bottle quickly. Moisture in the air could ruin the test strips.

7. Hold the test strip by the blank end, and dip it into the water sample for one second.

8. Remove the test strip from the water, and do not shake any excess water from it.

9. Hold the strip level, parallel to the ground with the indicator pads facing up, for 60 seconds.

10. Match the color of the pad with the appropriate color on the key that comes with the test strips to determine the level of nitrates in the water.

References

• USU: Nitrate Home Testing (PDF)
• Life Water: Water Quality Testing
• George Mason University: Nitrate Test Strip Instructions
• Colorado State: Nitrates in Drinking Water