Hi guys, first time recreational grow. Four plants from seed, sativa dominant. They were looking beautiful until this week when all leave started to dry out, older growth more than new stuff, but new leaves have twisted like crazy. Bigger leaves are brittle at tips, yellow tips, brown spots, stems look healthy. Have recently eradicated spider mites and added a copper solution to combat potential leaf curl fungus. Re-potted yesterday in case of over watering, but thinking could it possibly be cold stress? Lately it's been getting down to 5C-8C overnight, and they're growing outside in my greenhouse. Just growin in Osmocote-laced premium potting mix. Any ideas? Can't figure out how to upload images.