Iodine pill treatment can take 20 minutes or longer, and the pill's effectiveness is lessened in cold or murky water. Read the label to see if the manufacturer guarantees the tablet's effectiveness against Giardia, and follow directions for use. Chemical treatment can give a mild unpleasant taste to the water. If desired, add powdered, flavored drink mix to the water to improve the taste. Household bleach can be used to disinfect water.
Chemical treatment can impart an unpleasant taste to water.
Boiling water . Boiling water is a reliable method of destroying Giardia.