Before use, wash water bottle in top rack of dishwasher or by hand with warm soapy water. Water Bottle filters dont require soaking. Replace filter every 40 gallons or every two months whichever comes first. Remove filter from filter housing. Push new filter firmly into housing. Unscrew cap and fill bottle with cold tap water. Tighten cap firmly. Squeeze one full bottle of water through the filter to activate before use. When replacing the filter, look for item number 60258 35818 - the black Brita Bottle Replacement Filters.Substances reduced may not be in all users water.