The DM-1 In-Line Dual TDS Monitor is a precision tool designed for saltwater aquarium enthusiasts who demand high-quality water to maintain the health and vitality of their marine life. This monitor allows users to measure both feed water and product water TDS levels with unparalleled accuracy, thanks to its dual electrode probes that offer real-time readings through an advanced microprocessor system. It features a wide measurement range from 0 to 9990 ppm, ensuring it can handle any situation from freshwater adjustments to the most demanding reef tank requirements. Its auto-off function conserves battery life and includes easy-to-use Mur-lok® quick-connect fittings for hassle-free installation.