Systems, apparatus, and articles of manufacture for stand-alone chemical dispensers are provided.

A sieve-like filter unit, especially for a cartridge-shaped receptacle, which is arranged on a connecting port/connector of the receptacle and is designed to withhold undissolved powder and/or solid particles present in the receptacle, comprising at least two openings each being composed of at least two connected part recesses, wherein each individual opening in its entirety is formed to be extending in a non-linear manner.

An insert for a liquid-holding container may include a body comprising a wall, an open top end and a bottom end, and a generally tubular lumen extending from the open top end to the open bottom end. The insert may include a plurality of first openings formed in the wall, the first openings being situated between the top and bottom ends, wherein each of the plurality of first openings defines an area, and wherein the plurality of first openings have substantially the same dimensions. The insert may include one or more second openings formed in the wall, the one or more second openings being situated between the top and bottom ends, wherein each of the one or more second openings defines an area that is greater than the area defined by any of the first openings, wherein the one or more second openings have substantially the same dimensions.

An insert for a liquid-holding container includes a body comprising a wall, open first and second ends, and a lumen extending from the open first end to the open second end. A plurality of first openings are formed in the wall, each of the first openings defining an area, and one or more second openings are formed in the wall, each of the one or more second openings defining an area that is greater than the area defined by any of the first openings. The first openings are arranged in a first row of at least three first openings in axial alignment and a second row of at least three first openings in axial alignment. At least one of the one or more second openings is situated closer to the first end than any of the first openings, and each of the first and second openings is sized to permit the passage of a liquid.

An eroding assembly for use in water-soluble chemical feeder where a solid chemical material is eroded by water so as to produce a sanitizing solution of dissolved chemical and water having removal components in its structure for ease of cleaning and removal of any undissolved chemical material, particularly the sieve plate and weir.