Plants top leaves twisting, Zinc Def??

Hello community! I have another plant in my garden with some problems, It appears healthy but the leaves are twisting severely it has purple/red leaf stems and the leaves feel dry and crispy to the touch. According to the cannabible I could be dealing with a lot of things high heat, Zinc or Magnesim, IDFK. This is the first plant to show early sex and HOORAY its a Pistil! Helooow ladies!

Medium:FFOF, 1" hydroton @ bottom for drainage
1.5 Gal pots

Nutes/Water: H20 6.5, FF Grow Big general feeding (5 weeks), FF Big Bloom 2/3 Strength foliar(applied 2x), FF Tiger Bloom 1/2 Strength Foliar (applied 2x), Cal-Mag 1/2 Strength (applied once 2 days ago). Only water when top 1"-1.5" soil is dry.

Plants: Seed, 10 weeks from sprouting, genetics unknown

Environment: Photoperiod avg high 81F H44% Nightly Low 64F H24%, Plants 12" from lamp


Sorry about the weird angles, don't really know what happened...
Image1 Full plant- doing awesome with LST!
Image2 Leaf twisting and curling
Image3 Another angle of the top with leaf twisting
Image4 Same Top angle W/ flash
Let me know if ya'll need more, can't wait to hear your opinions, Thanks!

Have you checked your medium ph and run off yet?

ok first you should never put hydroton at the bottom of your pot. and your using a soil thats full of nutes already so you should not be adding anything at all but water

Really there is nuthing wrong with hydroton at the bottom of the pots, Its for the extra drainage and give oxygen a way into your medium. I grow soil i use washed river rocks in the bottom of my grow bags.. It might not do anything at all but its certainly not hurting anything so i dont see why you would recommend against it...and i agree as far as the only watering with plain water as FFOF is a fairly hot mix...Peace

pH runoff is measuring in at about 6.1

I like using rock/ hydroton at the bottom of pots bigger than 1/2 gallon (I fully agree with kingmat^^^) I found out that the FF soil was fairly hot so I flushed with only water for about 18 days; that was 2 weeks ago, I started re-introducing nutes on a small scale. So I thought that would flush some of the excess soluble nute leaving the less soluble FF soil nutes.

I think it could be drastic transpiration damage too. I clipped some tips of affected fans to help them shoot and to try and help transpiration by reducing surface area to cool. I hope this is ok!