Good pics Ben.
As mentioned, Randy did some studies on RC and showed no loss in calcium content in his large rubbermaid storage tub for kalk, even afetr a month or more. Just mix in some water when low and throw in a cup or kalk now and then. I think he cleans it out a couple times per year.
Many of us now does our kalk that way. Bens pics show a similar set-up. Randy even argued the non benefit of running a kalk reactor versus the tub method.