Copper is found in effluents and natural water both as suspended solids and salt.
A high concentration is toxic for plants and animals, which accounts for its rigorous monitoring by the authorities and in industry.
Lower concentrations are often employed to contain the growth of plankton and algae.
Ion selective electrodes used for measuring copper quickly become tarnished and need to be polished frequently or stored in costly EDTA solution for 1-2 days and suffer from temperature changes. On the other end of the scale, test kits are low-cost but highly inaccurate.
HANNA® offers an affordable meter with a custom microprocessor and large LCD as a viable alternative: HI 93702 with a resolution of 0.01 mg/L.