4 Weeks of Water in Flower...

This guy on bubblemans world from "house of the great gardener" is saying he puts his plants "on water for the last FOUR weeks of flower, always flush your plants, if the fan leaves aren't yellow there are still nutrients in your plants."

WTF? This is contrary to everything I've ever heard, seems he's just missing out on yield?

40:35

He must really be chelating the crap out of his soil with chemical nutrients. I've heard a week but never any more than that. They make flushing agents that should be used every 4 weeks with synthetic nutrients to keep lockouts from happening.

Just grow organically and don't worry about flushing period is the best way to grow imo.