Solid chemical dissolver and methods

A solid chemical feed unit dissolver 18 has an upper feed unit chamber 26 with an inwardly tapering sealing surface 20 at its lower end and against which a lowermost feed unit seals, retaining the upper chamber 26 in a dry condition, preventing wetting and caking of solid chemical feed units behind the dissolving and sealed off face of the solid chemical feed unit 18. A solid chemical feed unit magazine 16is slotted to permit gentle feeding of a plurality of solid chemical feed units 10 therein and a cover- defined sight slot permits guiding and visual observation of remaining solid chemical feed units in the magazine. The magazine 16 preferably, but not necessarily, defines the tapering sealing surface 20. Distinctly shaped solid chemical feed units 10 are disclosed. The dissolver can handle large solid chemical feed unit loads up to one hundred pounds or more and in a small footprint stable configuration. Also methods are disclosed.