Which method is commonly used for chemical disinfection in aquariums?

Using UV light for chemical disinfection in aquariums is a well-established method due to its effectiveness in killing various pathogens, including bacteria, viruses, and protozoa. UV sterilizers work by exposing water to ultraviolet light; the intensity of the UV radiation disrupts the DNA of microorganisms, preventing them from reproducing and effectively sterilizing the water. This process is essential in maintaining a healthy environment for aquatic life, as it helps control outbreaks of diseases that can arise from pathogens.

While other methods such as sand filtration, sedimentation, and reverse osmosis have their places in aquarium management, they do not primarily serve as chemical disinfectants. Sand filtration is mainly used for the physical removal of particulate matter, sedimentation also removes solids but does not address microorganisms effectively, and reverse osmosis focuses on removing ions and larger molecules from water rather than disinfecting it. Therefore, UV light is specifically recognized for its ability to provide chemical disinfection, making it the correct answer in this context.