Abstract: A bottle assembly includes a cap assembly, a bottle body, a base assembly and a filter assembly. The cap assembly includes a straw. The bottle body is removably connectable to the cap assembly. The base assembly is removably connectable to the bottle body. The filter assembly is connectable to the bottle body, and the filter assembly includes an aperture configured for passage of a portion of the straw. The aperture includes a mechanism that is closable when the portion of the straw is not in the aperture. A method of using a bottle includes removing the cap assembly from an upper opening of the bottle body and introducing fluid into the upper opening of the bottle body and through a filter assembly, the filter assembly including an aperture configured for passage of a portion of the straw. The method also includes closing the aperture.