How long to flush using Florakleen

I am going to use Florakleen as a final flush in a week or so. Sunday will be week the beginning of week 7 and my harvest date is 8-9 weeks. How many days should I flush with Florakleen and should I start flushing a day early to give the plant an extra day of just plain ph's water or will the Florakleen not saturate the plant?

Here's the way I learned it.

http://boards.cannabis.com/grow-faqs...cs-system.html

Thx for the n fo WH