Simple and safe control of aquarium water parameters. Determine the optimum pH for freshwater aquariums. Laboratory comparator system to compensate for self coloration of the water: fill plastic cuvette with water sample, add reagent to one cuvette, place both cuvettes in the holder, read off the values on the color scale Directions for use: in new aquariums once a day for the first week, then once a week thereafter Online laboratory: regular monitoring for a healthy aquarium with near-natural conditions. JBL offers quick tests or color change tests for all types of water analysis. Test aquarium water for healthy and clear water. Delivery: 1 quick test, pH 6.0-7.6 test. Sufficient for about 80 measurements. Includes reagent, 2 glass cuvettes with screw cap, syringe, comparator block and color scale. Refill reagent sold separately.