Hi everybody - first post (moved from "Getting Started"), first pool.
After moving to San Antonio last month we just moved into a house with a three-year-old pool. After reading a few things online, I quickly stopped using the previous owners' OTO test kit and bought a DPD kit from Leslie's. Finding this site later, I realize I should have bought the DPD-FAS, but I'll get one soon.
Right now I have a really basic testing question, though - how quickly do I need to read/record the DPD FC results? After adding my reagents to the test vial, the immediate result indicates a "1," but that changes over the next few minutes to a "3." So, is my FC 1 or 3?