Routine pool maintenance will help you keep your pool looking clean, sparkling, and inviting day after day. Pentair DPD, Bromine, pH & Chlorine testing kits and chemicals are manufactured under the strictest quality control standards in a laboratory staffed by certified chemists where all Test Solutions are formulated and packaged. To guarantee reliability, test reagents should be replaced annually. Replacement and bulk reagents are available in a variety of sizes and packaging.