rolling leafs

I need some help here are a couple of pictures of my plants that are looking weird. the plants have a ppm on the 500 scale of 1000 the ph is 5.9 they are under 1000 wt hps surounded by 2700k flor approx 2 months old temp air 74 day 64 night water temp 70 the water was real cold 58 last week I thought that was the problem so I got a water heater. the leaves were starting to curl inward I also put a couple of more pics of other plants in same box. Any help would be great The last picture the 2 leaves are from another plant also what causes leaves to feel dry even when they are green

Here is a good walk through (by mogie)to help diagnose your plant's problems. It appears that it may be for pic 3 that you aren't getting enough nutes.

Thanks I think the plant may need k lthough the ppm is now at 1400 I am going to add p and k to see what happens

Looks like there could even be some light heat damage near those taller ones, ive had similar lookings leafs that curl like that when burned by an hps. your room temp is good but whats the temp like right there where the light hits them?

I just moved the light up 4" and the 4 100wt 2700k up 8" the and moved the plant more to the side. The higest temp near the top of the plant was 86 some of my smaller ones are starting to do the same thing the stems are somewhat soft. I have different types of ferts maxi bloom in the bigger one power bloom in the #4 pic and 3 part in #3 I am trying to compare to pick one for the next group but that dosent seem to matter they all have some of the rolling. The water is pure 0 ppm so there is nothing in there the ph is stable Diagnosis is tough so I appreciate all the help. THANKS TO ALL

Ithink you possibly have a root rotting issue or similar problem. Are you giving them water every 3 hours or so? are you using some type of hydroguard solution?

Thats a great thought the roots on the real bad one it was a little brown and smelly I did just last night add hydroguard 50 ml for 8 gal I think that is one of the problems because as I said everything else seems to be ok I have also tried all the suggestions I have gotten. What causes that? THANKS

Here is a picture they are even more brown and smelly today I cut it out of the herd last night also and moved it to another spotLuckely it was in its own bucket.