I would continue the QC unless Michele, Barb or Ash tell you differently. Yes, 25% water change, then double dose of the M2 and 1.5 the dose of the plain M. One of them needs to initially start off with 2 doses the first day-sorry I can't remember off the top of my head so make sure that if it is the plain M then double that one also.

The M&M2 combo may cloud up the water or cause some foam on top of the water and this is normal.