Week and a half into flower, new leaves curling inward (PICS INCLUDED)

Hey all, Im on my second grow so Im still pretty inexperienced but its my first grow in my new setup and so far, I have had no deficiencies, no problems with my leaves or any problem with growth. Im less than 2 weeks into flower and already have little balls forming on bud sites which is good for less than 2 weeks because they are still stretching a bit. My problem is the newer leafs are starting to curl inwards in one of my plants (Blackjack) from nirvana shop but the other 2 plants are not showing the same symptoms. Blackback is like 6 inchs taller than the other 2 plants so its closer to the 600w HPS light but its a highly air cooled reflector and its not emiting much heat at all, its cool to the touch and the tops of the plants are like a foot away from the light. Im using the lucas formula at full strength 16-8 keeping my pH between 5.5 and 5.8 at all times. I water every 4 hours and only once during the 12 hours of darkness. Temps are between 70 degrees and 75 at all times during the day and humidity at 30 to 40% during the day and 70% at night when the tent is zipped up.



I am using an ebb and grow system I designed myself, using 5 gallon buckets with 10' bucket net pots. So far I have not had to cut any dead leafs because none of my leafs have burnt tips, or show any signs of deficiencies as I am proud if this because my first grow didnt go so perfect. None of my big fans have wilted thus far and only the newer leafs on top of the nodes are starting to curl inward. Is this genetics or is it conditions? Only the 2nd and 3rd picture shown contain the shots with the curling leaves, the other pictures are to show how the other plants are not doing the same thing at all.

Bump.......................

You have little balls growing on your bud sites? Having curled leaves if the least of your problems, you have hermaphrodites.
Post some better pics of w/e is curling up.

looks like u got urself a couple beastss