Leaves curling up, deficiency eventually killing plants. PLS LOOK AT PICS AND ADVISE!

I have always grown huge healthy buds under 600W HPS, temps stay in the 80's, I have a specific organic soil mix (soil, perlite, bone meal, dried blood, bat quano, Epsom salt, garden lime). I haven't changed much other than different brands of bat quano and Epsom salt because what I usually get is not available. I have recently got new seeds AK 47 and Candy Cush from Nirvana and it's been a disaster. Could it make a difference what kind of Epsom salt do I use? (Epsom plus vs Epsom salt..)? In the grow room they are only under 250W MH light and that's where the problem starts. All the top leaves (fan leaves and smaller leaves as well as new growth shortly after coming in) curl up. Just the edges of the leaves, all start slowly curling. Not the bottom of the plant though. As seen on the pictures. Shortly after I put them in the growing room, they start yellowing and having dead dried spots on the leaves, eventually completely killing the leaves. The second part of the plants with the yellowing are in the flowering room. The stem is also purple which I thought is just part of the AK 47, but I am starting to think it's something else. I really don't know what to do. BTW my soil pH should be fine because of the lime and I use tap water, but balance pH to about 6.8 with fish tank staff, which also removes chlorine and other metals. Has anyone experienced this? Please help!

Looks environmental to me.

Peace.
Tav

Have you checked for broad mites?


My initial suspicion would be a magnesium deficuency if no broad mites are found.

Too much calcium from the lime could be blocking uptake of Mg.


PH 6.5 or below for best absorption of Mg.


Use something like a mono Mg nutrient to help.


Mg def usually starts with leaf edge curl up then followed closely by paling of the leaves, followed by brown irregular rust spots, followed. By leaf die off.

Red stems are indicative of a few nutrient problems usually N, P and Mg.



J

Your days of growing with hot temps are over these new strains are sensitive and need it below 80.