Algaecide & Shock: Can You Use Them Together? - Pool & Spa Expert

It is generally not recommended to use an algaecide and shock treatment simultaneously, as this can reduce the effectiveness of the algaecide. Algaecides are designed to kill algae, while shock treatments are used to raise the chlorine levels in the water to kill bacteria and other microorganisms. When used together, the shock treatment can reduce the concentration of the algaecide in the water, making it less effective at killing algae.

As a result, it is best to apply algaecides and shock treatments separately, allowing at least 24 hours between applications to ensure the algaecide has time to do its job. Additionally, it is important to follow the directions on the product labels for both the algaecide and the shock treatment to ensure their safe and effective use.