Light, nute, wind or heat burn?

My first guess is heat, maybe raise the light a bit as those 1000w hps lights get real warm. Also I would back the nutrient strength off a bit as I think it was 3.4EC according to your diary and that’s very very high in anyone’s book. I think I saw a few leaves in your diary where the tips looked a little burnt and pointed up which is a indication it’s a bit too much for them. Camera angle made it hard to see clearly. Your room ambient temp is ok according to your diary but maybe under the lights it’s a little warmer. Back the nutrient strength off a bit, create a larger gap between the lights or try and drop the room temp down a bit and observe for improvements👍Looks good though on a whole