Flush? What in the world for?
In what?
Soil?
Coco?
Let me guess, overage and Jorge says to flush......FAH!
I never flush for any reason in soil. Simply straight water - pH'ed to 6.5 and maybe add a Ca/Mg as I'll bet it involved a pH problem...
7-10 days and then start the nutrients right back where they should be used on the feeding chart.
Coco salt flush? (You should do this now and again) Start the nutes back at the next watering.