First Grow 17 Purple Kush 1 Mango Kush

Hi this is my first grow!, I will try to give as much info as possible, all comments, advice are welcome! These babies were all given to me by a friend he gave me a little advice on how to proceed and believe it's time I get more knowledge from different people, the more knowledge the better no? So I will also show pictures up until the day it is ready!!

I'm using/have the following:

• 2x-1000w HPS
• 18 Babies (17 purple kush and 1 mango kush---the stretched out one in picture below)
• Pots are a little over the place ranging from 1Gal-5Gal
• I believe when I got my babies they were transplanted into COCO?
• I use FOXFARM - Big Bloom, Grow Big, Tiger Bloom(using recommended dosage)
• Water every about 2-3 days( until I see a little run off from bottom)
• Room temp is between 20-23 Celcius lights on and 15-17 lights off (currently in 12/12)
• Using NO CO2 other then when I smoke in the room.(IF that even counts)
• No carbon filter I'm using 2x Oreck professional machines for the smell( works like a charm)
• They measure about 27 inches high and 20 inches wide

I know in some of the pictures you might see black rays I tried to angle best I could for it not to happen, I know some of them are clawed (probably due to using recommended dose of foxfarm and using all 3 products at sametime every water, I will flush next watering). Pictures are missing about 3weeks of veg but I have from when I received so 1 week few days of veg + 1 week 1 day of flowering I believe I might have taken some inbetween o.0 i'll have to look through my photo's..

First picture is when I received them, the second is the day after transplanting... the rest are from today

So I've come across something suspicious , I have some leafs that look like are dying off, while curling from the sides(downwards) i'll have a picture when I open my lights in 12h .