The Water You Drink

Investigation Protocol

1. Collect water from the tap in a prepared, clean beaker. 
   To do this, first run the water for 1-2 minutes to make sure you measure fresh water, instead of any "stagnant" water collected in the pipe.  Then pour the water into the beaker with a light stream. Keep the beaker tilted at a slight angle so the water pours down the side of the beaker. This will prevent the creation of bubbles of air in the water (see picture below).
   
2. Measure the acidity of the water you collected. Measurements can be taken with a digital pH sensor, a laboratory pH-meter, litmus paper (strips) or other indicators of acidity.
3. If you are using a digital pH–probe or a laboratory pH-meter, then it is neccessary to pre-calibrated them. (see Project «Getting on the Same Page». Repeat the test three times, each time washing thoroughly first, and then wiping the sensor dry. Enter all three measurements in the Report. The program will automatically calculate the average value, summing these three values ​​of acidity and dividing the total by 3. The resulting value will be considered the average acidity. (You will see the results at the time of sending Reports. They also can be viewed in the "Results" section in your profile after it is sent.)
4. If you use a litmus test measurement of acidity, it conducted as follows: Dip a strip of indicator paper in the test solution, then put it on a white waterproof substrate and quickly compare it to a reference color scale. This will give you the value of the acidity of the liquid. A measurement using a litmus test, as in the case of sensors, should be repeated three times and all three values ​​taken to make a profile.
5. Fill in the Report Form.
6. Periodically – once in a week or two – check the acidity of the tap water, and in each measurement fill out a report, being sure to note what natural phenomenon that can change the acidity of the water in your area occurred between measurements.
7. Follow the progress of the project, participating in the discussion of the results obtained by other contributors.

Safety tips

Use caution when working with electrical appliances such as the pH-meter. Follow the instructions for use.