Im am fucking sick of these arguments. There are legit reasons a flush would be necessary, and excess (usually alot of it) can cause chemically tasting weed. I just got the grow bible by cervantes to go along with my one by green (both great).
"how to tell when fertilizer will affect taste:
1. leaf tips and fringes are burnt
2. leaves are brittle at harvest
3. buds crackle when burning
4. buds smell like chemicals
5. buds taste like fertilizer"
On page 76 it says "ten to fourteen days before harvest, flush the garden with distilled water or water treated with reverse osmosis"
Im not saying it is always needed, but certainly sometimes is.
Tell me Cervantes is wrong people. Cmon