In the tubes with less balls, (0, 1, 5, 10) the colour of the indicator was more yellow toned indicating pHs of (7.6, 7.8, 8.1/more acidic) due to the higher amount of Co2 dissolving in the water forming carbonic acid. While the tubes with more balls (20, 30, 40) were more purple toned indicate pHs of (8.6, 9.0, 9.1/more alkaline) as there is less Co2 dissolving in the water as it is being used as an input for photosynthesis by the algae balls.