Chlorine is still the best defense against bacteria and more…

Can the COVID-19 virus spread through pools and hot tubs?

From the CDC 3/16/2020: There is no evidence that COVID-19 can be spread to humans through the use of pools and hot tubs. Proper operation, maintenance, and disinfection (e.g., with chlorine and bromine) of pools and hot tubs should remove or inactivate the virus that causes COVID-19.

When chlorine — sold as a granular powder, liquid or sometimes in its elemental form as a gas — is added to water, it forms a weak acid called hypochlorous acid. This acid is very proficient at killing bacteria such as salmonella and E. coli, and it also knocks out many viruses.