Nute Burn?? Potas Def?? PLEASE HELP ASAP!! PICS

If anyone knows what this problem is and could help me cure it before it gets any worse i would greatly appreciate it. Room has more than enough ventilation, many fans and temps at night are around 75 and 85 during the day. Running 2 1000watt hps and 2 600hps for 6 of the ladies. I use advanced nutes, micro, grow, bloom, big bud, carbo load, hygrozme, and enggys f1.... ph is ALWAYS between 6.2 and 6.5.... My clone, and veg is flawless but everytime about the 3rd week of flower the ends of the leaves start turning brown and follows up the edge of the leaves some ends curl some dont, mostly effects fan leaves first. I have tryed many options in the past and nothing has worked so now i rely on U. Help me out.....

its either nute burn with all them nutes ur using, i would do a plain water diet for a week or there too close to them lights im running 1000watt light i burn the end of mine you got so much light there they should be real nice HTH

looks like bad nute burn to me....I would flush them a lot and raise that PH a little 6.6-6.8, assuming you're in soil.

ya you gave them a bit of nutes...keep it simple, some strains dont like a lot of nutrients

So I should flush them out... There in 5 gal pots so use like 10gal per pot of ph 6.5 water with no nutes and thats it or when im done flushing should I give a 1/4 strength nutes?

try and give 1/4 strength .. and see what happens after long flush