Leaves curling/hooking/clawing on Sativa dominant Sour Diesel Clone

Things have been going very smoothly, when in the last couple of days or so 1 of my 2 Sour Diesel clones has begun clawing and hooking. All of my plants are on the same feeding and nute schedule, and are handled literally exactly the same. I was wondering what causes this to happen, as I have read that sativa heavy strains are very susceptible to this. Here are some pics of the affected plant, as well as its sister clone, which is having no problem what so ever. I have given her a light flush (2gal water in a 3gal pot) and will feed her only neutral water for the next week and see how she responds. This is a new problem for me, and was wondering what your experience with this has been ... thanks!




Here is the sister plant




Here is a link with my specific grow details: https://www.rollitup.org/indoor-growing/567104-8-budding-plants-3-different.html

yeah i had some plants do this, mine was high PH. i grow dwc

I've had that happen to me to on my last grow its a ph problem I use lime juice to fix it

But my runoff was 6.5-6.8 and none of the other 8 plants are showing any sign of this....... this is very confusing

Over watering. Your roots are sitting i stagnant water.

[video=youtube;5AypYXJ0cKg]http://www.youtube.com/watch?v=5AypYXJ0cKg[/video]

well when i flushed it today, it had the same dry but not over dry consistency that my plants always have when ready for watering.... If it was something obvious such as rotting roots I wouldn't have posted this here... It is impossible for them to be sitting in stagnant water... or any kind of water for that matter. Beyond that, they were transplanted 10 days ago so I know that the roots are not water logged.

anyone with any constructive ideas besides, cal/mag,epsom salt, or watering? It is none of the obvious ailments.