White-Spot is a parasite; the adults live on the fish and appear as tiny white spots similar to grains of salt. The adult detaches from the host fish and then releases hundreds of cysts which burst resulting in free swimming juveniles looking for a host fish to infest. Anti-White Spot & Fungus is a 7 day course of treatment which will eradicate White-Spot, other protozoal parasites & fungal growths.