An ORP meter, also known as an online oxidation-reduction potential analyzer, is an instrument widely used in industry and laboratories. ORP, as a comprehensive indicator of the environmental conditions of media (including soil, natural water, and culture media), has been used for a long time, characterizing the relative degree of oxidizing or reducing properties of the medium. The unit of ORP is mV. The ORP value (oxidation-reduction potential) is an important indicator of water quality. Although it cannot independently reflect the quality of water, it can be used in conjunction with other water quality indicators to reflect the ecological environment of an aquarium system.