Control of water softness also means reduction in scaling of the aquarium and filtration system like the water pumps. it is very expensive to service water pumps. if they get choked or if the water lines are narrowed, the pumps overwork and finally break down. therefore, maintaining water hardness will prolong the life of the pump.\nrange: 0 to 1000 µs\nresolution: 10µs\naccuracy: ±2 % full scale\noperating temperature: 0 to 50°c or 32 to 122°f\nautomatic temperature compensation: 0 to 50°c or 32 to 122°f\nbattery : 4 x 1.5v button cell (alkaline)