I am planning a Biology investigation for my IB IA on the impact of temperature and pH on algae growth. Does anyone have tips on how to measure the growth rate of algae? What algae is the most suited for such an experiment? Also, how do I change the pH of the water containing algae? I'm a beginner, any ideas would be a great help!
In general is a good idea to check the scientific literature in the subject. In the section "materials and methods" you could find how people do stuff like measuring growth or controlling pH.
Of course, many of the methods described there could be out of reach, but you can get ideas and ask here more specific questions.
For this specific question a quick search lead me to this paper "Standard Methods for Measuring Growth of Algae and Their Composition"