For a science project, Im testing different water sources for hardness, chlorine, etc, and comparing them to tap water. What are the independent and dependent variables?
The independent variable (the one that YOU can vary) is the selected water source. In this case you have a few different sources, including tap water, that you would identify and describe. The dependent variables are the properties of the water that you will measure with each sample. Good luck with your project. Sounds interesting!