Science Buddies: "Ask an Expert"

Hello! I have several global projects, but I am sure you need to focus on one problem in order to cover the issue in the right amount. Skills in economics allow me to choose one of two topics. I wanted to combine them together, but creating a plan, I realized that I’m going to get a lot of information than I planned.
1) How positively the review sites influence, on the example of the similar: https://wisepick.org/best-whole-house-water-filter/
2) The benefits of a cleaning filter for water and a self-made filter. Here it is possible to partially use this information for the first part https://en.wikipedia.org/wiki/Water_filter.

I would pick whichever project is the easiest to test. What materials are available to you? How are you going to measure your results? Etc.