I guess we will find out if the fan off helps. But you should get a meter and do the slurry test on the coco from the pot, but let the coco and water sit overnight then try testing.
Did you wash band soak your coco before use? The runoff is Important, because it's a more accurate representation of what the plant is experiencing. The temps are slightly high, but nothing that would cause your problems.
When you're "flushing", it's really just leaching salts from the soil. The plan still retains everything it's already absorbed. So, when you feed it again you're just adding AGAIN to the toxicity problem. In my experience, toxicity really increased the time it took to finish, not really...
You are murdering that thing. The leaf cuping is a sign of under watering. Also, cut back on the phosphorus it's too abundant causing a lockout of zinc. That's why you are having pale leaves and grayish patches.
Why do people still believe the arbitrary circumstances surrounding someone's "race", play any role in their character. You are retarded if you think a slight variation in skin color, or facial features means anything. That, or you have a tiny pp.