The Frog Maintain 10-01977 is a maintenance shock dose to be used once a month with the Frog @ease system. This non-cholrine oxidizing shock, breaks up organic material to help maintain water clarity. We recommed adding a packet everytime you change the Frog @ease Smartchlor grey cartrige .
If your spa gets heavy use and need to shock more than once a month we recommend : Spa Pure Oxidizing Shock which can be used weekly or even after each use.