? #1 => Yes, turn the unit down as needed.

? #2 => Do NOT raise the calcium level, yet.

? #3 => Not necessarily, CYA can take several days to dissolve.

And, more:

4. Do try to run high CYA (~80 ppm) for most SWCGs; Do NOT try to run 1 - 3 ppm FC -- it's too low.

A number of guys are running SWCG systems with FC = 5% of CYA . . . but many of them (most?) are in western, or west coast areas that are dry and do not have the humidity, thunderstorms and the like that can leave algae in every bit of dirt and on every leaf. I'd recommend the higher levels you see in my Best Guess Chart (blue signature block).