From prior knowledge, we know that when you add CO2 (carbon dioxide) to bromothymol blue the water will turn green, when you add O2 (oxygen) the water will turn blue. The experiment we investigated is how does the amount of light the plant receives affect the color of the water. We took three test tubes with water and bromothymol blue, two of them had elodea plants in them one of them the control did not. One of the test tubes with the elodea plant in a dark cabinet where no sunlight could reach the plant, the other tube was near a window. The control was also near a window. We recorded the color of the water after 2 and a half days. After putting together our knowledge and researching we developed a hypothesis: If we put an elodea plant
