Mephisto love (over 2lbs!!)

Hello guys! It was such a disastrous week. Everything was going great until yesterday when I received a 1000w HPS with a electronic ballast. I was running 600w before without any problems with 180m3 exhaust fan. Silly me thought it was okay to run it. I even set it to super lumen mod lol. Couple hours later I smelled smoke coming from my room and realized my exhaust fan stopped working. (Later i found out it has running temp of 40 C) As a result my duct started to melt. Now I'm running my old 600w on half power around 300-400w in between plants without any need to cooling. Also put couple leds to sides for now... I ordered a new exhaust fan 4x big what i use now.. So i think i will be able to run that mf 1000w in couple of days. Apart from these news, plants are doing amazing. however, they have some problems. Mostly upper leaves are curling and i am getting nute burns every time. I was taking any run off before a week ago so thats gotta be the problem. Run off ppm is around 400-1000ppm. So i thought no need to flush but as i said started to taking run offs every watering now.. Flower formation just began on most of them. Stretch is finally over. I wanted small and compact plants but look what i got... well i can't complain^^ scrog no more bcs they are all at different heights. Also started to supplement with diy co2 generator. I think its working. peppers grew tremendously last week!!