A Hoshizaki crescent cuber builds crescent cubes on a vertical stainless evaporator plate as water is circulated over it, and the water that does not freeze is pumped around and eventually dumped. Every freeze cycle leaves minerals behind. In soft water those minerals barely matter. In Twin Cities municipal water they add up: a thin, chalky layer forms on the evaporator plate, the water reservoir, the spray tubes and the float switch. The layer insulates the evaporator, changes how the ice releases, clogs the small holes that spray water, and can make the float switch stick.
That sequence explains the symptom pattern we see on KM cubers and F-series flakers. Production slows first. Then cubes start to look incomplete or cloudy, or a flaker begins to groan as ice drags against a scaled surface. A water leak may show up when the float switch or a fitting stops sealing properly. By the time a machine stops entirely, there is often a year or more of mineral buildup behind it. The good news is that scale responds to cleaning, and most of the damage can be avoided by cleaning before the machine stops.
Hoshizaki recommends a descale and sanitize schedule that is shorter in hard-water areas, and that is the guidance we apply to Twin Cities machines. If your machine has never been descaled and has been in service for a few years, expect a more involved first cleaning than a routine one, and tell us in advance so we can plan the time.