FreshWater MPS Test Strips | Non-Chlorine Shock

FreshWater MPS Test Strips are the dedicated dip test for spas running on a non-chlorine shock program — also known as MPS-based water care. A single 2-second dip measures three parameters at once: MPS (monopersulfate) level, pH, and total alkalinity. For owners who use MPS as their primary oxidizer, this is the diagnostic that confirms the program is working. MPS (potassium monopersulfate) is the active ingredient in non-chlorine shock. Unlike chlorine — which both disinfects and oxidizes — MPS only oxidizes. It breaks down body oils, sweat, sunscreen, and other organic load without adding chlorine or raising chloramine smell. Owners pair it with a smaller chlorine residual (often via Ag+ Silver Ion programs or low-output salt systems) to get the comfort of a "low chlorine" spa without sacrificing sanitization. This bottle contains 50 individually accessed strips sealed in a moisture-resistant flip-top container — roughly a year of weekly testing for most owners, or six months if you test before every soak. Pro Tip: This strip does not test for chlorine, bromine, or hardness. If your spa uses chlorine or bromine as the primary sanitizer, you need FreshWater 5-Way Test Strips instead — those test chlorine, bromine, pH, alkalinity, and hardness. The MPS strip is for MPS-based programs specifically. Brand FreshWater®