Dissolved Oxygen September 28, 2103

In class, we all took turns finding the dissolved oxygen level, the temperature, the conductivity, and the pH level of each of the four bottles (seen in the picture). The first bottle is the control and contains only gravel and tap water. The second bottle has gravel, tap water, and a plant. The third bottle has gravel, tap water, a plant, and salt water in it. Finally, the fourth bottle contains gravel, tap water, a plant, salt water, and a fish. We found that the dissolved oxygen level went down with each bottle, indicating that the more substances or organisms that are in the bottle, the less dissolved oxygen there is. The temperature and the pH level remained fairly consistent throughout each bottle. We also found that the conductivity rose with each bottle, showing that with every substance or organism put in the bottle, the conductivity rose.