EUREKA!!! I've solved the riddle!
BRS had changed the concentration of their calcium chloride. The older formula was 2 cups per 1 gal of water. The new formula is 2.5 cups per gal. I order it in 5 gal pails which I keep in the garage. From it, I fill a 1 gal pail which I use to mix the solution. Labour day weekend I spent up the lake and my tank sitter for some inexplicable reason switched this 1 gal pail with an older, formula one gal pail I was using for the frag tank in the basement. So, therefore when I made up new solution I was using 2.5 cups of the older, more concentrated calcium chloride instead of 2 cups and was unknowingly overdosing the last two weeks.
