I don't think the dots from cal def heal. Also, Ca, like mg, takes a while to show up, may also take a while to recede.
So, if it halts the spread expect it to be working.
You have a strong canopy and have time to be patient and do this conservatively and in a smart way.
check your pH :P it really is important, i am just kidding, but if you don't control it, it's basically worthless to give suggestions. more akin to blindly stabbing in the dark.