I haven't hit lockout yet, but i do have my epsom coming in on wed. for flowering. (I still use some of my AN stuff, so the bud factor x, is pretty much epsom salt-water from what I can tell) since adding my filter and seeing what happened to the next 2 grows, I add light dosage of calmag every water, with strong doses here n there as they get larger.
I'm still honing in my cal-mag treatments, but so far, much better than previous.