Well the trichomes are turning amber and its week 9. I change reservoir every two weeks. I always start flushing near the end.
Ok. Are you checking the trichomes on the leaves or on the calyxes? That plant has 3-4 weeks to go probably.
Also, flushing does not help improve taste, smoothness or potency in any way. There have been recent studies proving that and I also did a side by side comparison of two same-strain plants. All the leaves died on flushed plant, less yield but same flavour and aromas because I dried and cured them properly (It would have been more accurate comparison if they were clones of course).
It all comes down drying and curing. If you're flushing, you're depriving your plant of nutrients DURING THE MOST CRITICAL part of it's life. You cannot just "flush nutrients" out of the bud.