I highly doubt that it's a cal/mag issue. Grow/micro/bloom has pretty much all the macro/micro's. Read the labels, as I use Connisuer 2 part, not the 3 part, and my plants chug along just fine, and I've never had a "salt buildup" issue that required me to "flush" my plants. Since you've flushed them, I'd feed them a half dose a couple days apart. A couple of dying leaves that far into bud, I wouldn't even sweat, just pluck them and move on.