The HI781 is designed specifically to measure low levels of nitrate in a saltwater aquarium. The 0.00 to 5.00 ppm (mg/L) range is ideal for saltwater, reef aquarium maintenance. Like professional instrumentation that use a light source, filter, and light sensing detector, the Hanna Marine Nitrate Checker? uses a fixed wavelength LED and silicon photo detector to provide the accuracy of professional instrumentation at the affordable price of a chemical test kit. Compact, Portable Design Built-in Timer Saltwater Compatible
