Problem with leaf curling down please help *PIC*

So after searching the plant problems section for an hour i decided to reach out to RIU for some help. My 4 other girls are not exhibiting any of the symptoms of this girl. I am thinkning heat strees, under/over watering (although the pot was nearly bone dry when i watered last night) or some sort of deficency. The soil is a mix of Schultz's organic potting and Miracle Grow Organic with perlite mixed in. Could the nutes in both these soils be killing it? I moved my lights (4 x 26 watt CFL) about 6" away from her in an attempt to heal her. Any input is greatly appreciated. (My other plants are in 100% Fox Farm Ocean Forest)

What about humidity? my leaves were curling a bit before I added a humidifier. But not to that extent, I'll admit.

humidity is at 29%

that's kinda low; especially during vegetation.

Try misting the leaves 2-3 times a day and see what happens.

yea humidity is really low bro 65 is optimal i dont like to use miricle grow for any of my ladies i have had serious issues with newt burns abd all other leaf necrosis issues but others have had luck, if the rest of you plants are good and not showing signs of this and are the only ones in ff soil than i think you may have the issue solved..

oh i forgot to add it's been flowering a week now (a week since the first pisils appeared)

bumpin' it on up.