Abstract: A system, that may be portable, for purifying liquid flowing gravitationally from a source/reservoir into a purified liquid receptacle is described. The system includes a housing with a generally horizontal filtering space. More than one liquid inlet disposed at a top portion of the filter is provided as well as one or more liquid outlets disposed at a bottom portion. The liquid flows in a generally lateral direction through the liquid treatment medium. Two or more first walls extending upwardly into the filtering space from a bottom wall thereof and ending with an apex are provided inside the device. One or more second walls downwardly extending into the filtering space from a top wall thereof are also provided. Each of the walls defines a closed path. The first and second walls jointly cause the liquid to flow in a curvilinear flow path from the inlet to the outlet.

Abstract: The present subject matter provides a filter medium for filtering aqueous solutions, particularly water for human and animal consumption. The medium may be employed in a great variety of filters of various sizes and constructions.

Abstract: An indicator for the status of the filter is provided. The indicator comprises at least one erodable member in contact with the source fluid and a visual indication arrangement that permits a viewer to gauge the appearance of the erodable member to thereby gauge the filter status. The erodable member is eroded by interaction with the fluid or with an element within the fluid. The indicator may be incorporated as an integral component of a filter or may be a stand-alone device to be incorporated into a filter or filtration system.

Abstract: A water treatment device and method for treating a quantity of water is powered by gravitational flow. The device includes an upper collecting chamber (14) and a filtration chamber (18). The filtration chamber includes a set of reactance containg at least three components wherein one of the components is a polycation and another one of the components is a polyanion. The method includes subjecting the water to gravitational flow through the filtration chamber (18).