When I did it, It was too much nute problem, so the flush (not the last two week one, but the 1 gallon ph'd water per gallon of dirt.) did help me. As to the last two week flush, I go from 1 tsp per gallon vs recommended. 1.5 tsp and continue to feed that. My thought is, unless you have over nuted the poo out it, no need.I’ve only flushed once trying to bring my PH up. I don’t think it helped diddly squat I never flush at the end either but I do give a drink before harvest. Makes my wet trim easier I think.