Pool Water Guide: Test First, Then Buy

Why it surfaced

Its most memorable feature is its unusually candid editorial policy: “We have never put a test kit in a pool,” so it compares products against published data and reported buyer problems instead of pretending to have field-tested them. The guide also adjusts its advice by region, showing why a Phoenix pool and a Boston pool may need different chemistry decisions.

A regional pool-chemistry guide with calculators for chlorine, cyanuric acid, shock, tablet use, and water replacement.