Method and kit for treating recreational water

A method for treating a recreational body of water having a water filtering system and a water recirculation system after a release of Cryptosporidium oocyst and/or Giardia cysts, wherein the recreational body of water has an initial active free halogen concentration between about 1 ppm and about 8 ppm, said method comprising:

• (i) adding a halogenating agent to the recreational body of water to raise the concentration of the initial active free halogen to a level between about 10 ppm and about 100 ppm;
• (ii) adding an agglomeration aid to the recreational body of water at a level between 0.1 ppm and 3.0 ppm, adding a filtration enhancement aid to said filtering system, or adding both an agglomeration aid to the recreational body of water at a level between 0.1 ppm and 3.0 ppm and adding a filtration enhancement aid to said filtering system;
• (iii) recirculating water from the recreational body of water with said water recirculation system through said water filtering system for a period of time;
• and
• (iv) reducing the concentration of active free halogen to a level of between 1 and 8 ppm in order to return the concentration of active free halogen to a level prior to adding the halogenating agent.