The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.
Cryptosporidium parvum is one of several species that cause cryptosporidiosis, a parasitic disease of the mammalian intestinal tract.
Cryptosporidium is a small protozoan parasite, measuring about 3-5 µm. It lives on (or just under) the surface of the cells lining the small intestine, reproduces asexually, and oocysts are passed in the feces. Transmission of the infection occurs via the oocysts. Many human infections have been traced to the contamination of drinking water with oocysts from agricultural "run-off" (i.e., drainage from pastures), so it is considered a zoonosis.
C. parvum is considered to be the most important water-bourne pathogen in developed countries. It is resistant to all practical levels of chlorination, surviving for 24hrs at 1000mg/L free chlorine.