Digital PDF, 34 pages. Most filter shopping starts with the filter. I made this guide to help you start with your water instead. Learn what to test, how to collect a reliable sample, how to read your results, and how to match a contaminant to the right treatment claim. Includes filter comparisons, steps for concerning results, maintenance guidance, a lab-report walkthrough, and a printable results worksheet. You get one clear process instead of scattered research. Read it on any device or print it at home. No physical item is shipped.