The 1 gal Test Solution #2 Phenol Red Reagent is an essential tool for accurately measuring the pH levels in your pool or spa water. This high-quality reagent is specifically formulated to provide precise pH readings, helping you maintain balanced water chemistry and ensure a safe swimming environment. Its red color makes it easy to identify, and it is commonly used in conjunction with a pool test kit. With a generous 1-gallon size, this reagent is perfect for frequent testing and ongoing water maintenance.