sick

Im in the process of growing a Northern Lights Auto. It's been going well for the most part so far, except it hasn't flowered yet. It's about 7 and a half weeks old. Today I opened the door and it seems like he new growth is curling. It didn't look like this before (not as bad anyway) and now...

I have had this problem is 2 grows now and have tried to get help and went threw my whole set up etc etc and never found the problem. I never go over 500 ppms with flora nova grow big bud etc etc. I water once daily and thats when they droop bad. Am I feeding them too much too little watering...