My opinion on flushing is
I have an outdoor growing friend who digs a hole big enough to bury a cow in, and he thows the dirt away and fills it back up with composted old dead cow shit, chicken shit, bat shit, sheep shit, and all kinds of nitrogen and 4 bales of peat moss. He grows trees as tall as his house. When harvest time comes, how could he possibly flush them? And his pot has NO Fertilizer tastes and NO chemical tastes.
Have you ever bought maui-wowie or mexican or columbian or jamacian pot grown commercially? Did it have a chemical or fertilizer taste? I bet not, and I bet it was not flushed. How would or how could anyone flush a field of pot?
Do you starve a cow a week before you butcher it or do you fatten it up all the way until butchering time?
A plant absorbs the nutes or fertilizers and converts them into useable food. The leaves do not have nutes in them, and the buds do nto have nutes in them.
I flushed my first hydroponic grow. It tasted sweet. I did not flush my 2nd, 3rd, 4th, 5th, 6th, 7th grow, and it tasted sweet.
Even a condemned murderer gets a final meal.