nute burn to flush or not to flush that is the question.

Ok 4 weeks into flower, I believe I see nute burn on the tips. I used heavier than normal doses of nutes because I noticed they seemed to be slightly yellowed or light green so I thought it was under feeding. Anyways my question is should I do a flush? Should I just water normal with JUST ph'd water. followed by light nutes every other feeding till the end? If flush is recommended should I do it now while the soil is still wet or wait till they are dry and ready for another water (3 days). Being this far into flower and never really had a successful flush before I'm stumped. It seems like flushing in the past has never really helped any problems but made more. So now I just try to stay away from needing to flush. Any input is appreciated.

promix
5 gal pots
advanced nutrients
hps
ph perfect nutes
typically half dose
good air flow
good temps
not over watered
not under watered
Sorry i don't have pics