I'm doing a school project in testing the water quality of 5 different fast food restaurants.
I recently bought this kit for testing:
*bacteria
*lead
*nitrates
*nitrites
*chorline
*iron
*copper
*pH
*alkalinity
*hardness
*pesticide
But I am only allowed to test for one thing, so i was wondering which would be the best thing to test for in the drinking water from fast food restaurants.