How far along into flower are you? If you are asking if you should use CalMag Plus the last 10-14 day's before you harvest? The answer is ok up to the last 7 day's then you flush everything. I like FloraKleen to flush my plants with either dirt or Hydro it works well and 8 bucks it's a good price. The last 7-day's before harvest you should only use water or water with a cleaning flush solution.

Is that what you are asking?