The Difference in pH of Lakes and
Ponds in the
Miranda Petrick and Carina Macorncan
We tested the difference in pH in the water of Lake
Michigan and ponds in the
Keywords: pH, lake, ponds, acidic, neutral
pH is one of the
many characteristics that are helpful in determining the quality of water for
living. pH is a measure of whether water
is acidic or basic (Stevens, 2009). pH
in this case measures the concentration of hydrogen ions in a chemical solution
to determine the solution's relative acidity or alkalinity (WDNR, 2010). In
Plants and other vegetation depend on photosynthesis and respiration for survival, these both can change the amount of CO2 in the water. When the plants use solar radiation, water and CO2 to produce sugar and oxygen, it results in a reduction of acidity and an increase in pH (WDNR, 2009). The connection between pH and photosynthesis is that the vegetation creates a higher pH level. Here, we can infer that because of the greater surrounding vegetation in ponds they will be less acidic than the lake.
Acid rain can lower the pH because of carbon dioxide in the air dissolving in water to produce a weak carbonic acid solution (WDNR, 2009). Filtering water and debris from waste in water can also change pH. We hypothesized that the pH level in the lake will be more acidic while the ponds will be less acidic.
Methods and Materials
On October 30, 2011 between approximately 1300 hours and
1500 hours we conducted our study in
There was a significant difference between the pH levels in the lake and ponds (Fig. 1, P=0.002).The results show that the pH of the ponds was more basic than the pH of the lake. The mean pH of the ponds was 5.9 with a standard deviation of 0.34. The mean pH of the lake 4.9 was with a standard deviation of 0.79.
Figure 1. Mean (+/- S.D.) of pH in water of ponds and lake.
Our data supported our hypothesis that the pH level in lake water will be more acidic while the pH level in pond water will be less acidic. The difference between the two groups was significant (P value= 0.002). If we were to repeat this experiment again we would use a different tool to read pH. Our interpretations of the color could have been inaccurate and we feel that if we used a pH meter with electronic readings it could be more accurate because it has a broader range. Also, we would like to test different bodies of water across the world to compare the pH levels. We would test water from different rivers, streams and oceans.
There might be some limitations to this study like the pH strips. We found that it was difficult to read the exact measurements of color on the pH strips so this could be one possible influence on error. Another factor that could have affected the pH levels was weather, the day of the experiment it was raining. Acid rain can affect the pH making it much higher than normal. This acid rain can be a result of pollutants from motor vehicles, chemical plants and other factories (Shea, 2008). If a body of water becomes more acidic, there is a chance that only certain organisms will be able to survive. This can cause a loss in species diversity and reproductive success (WDNR, 2009). Finally, the day of the experiment was very windy which could have blown any rain into the ponds or lakes that may have been somewhat acidic resulting in a change in pH.
S. (2008). acid Rain, Rain Go Away: Some Adirondack lakes are showing promising
signs of recovery.
Stevens, R. (2009). Fish Pond Water Quality: As Simple as Chemistry 101. Retrieved from http://noble.org/AG/Wildlife/Fish-Pond-Water/index.html
Wisconsin Department of Natural Resources. (2009).pH-acidity-understanding lake data. Retrieved from http://dnr.wi.gov/lakes/publications/under/acidity.htm
Wisconsin Department of Natural Resources. (2009). Carbon dioxide-understanding lake data. Retrieved from http://dnr.wi.gov/lakes/publications/under/carbondi.htm
Department of Natural Resources. (2010). Acid rain in