Using an IWS system, 3 x 2 meter tent, 5 600w lights. I don't ever montinor PH levels. Never have done to be honest. Never had this problem before. The tent got ripped on one of the door panels at the top of the panel, creating a sort of 1.5metre x 30cm gap at the top of the tent. Strangely enough, the plants near this gap appear to be ok, but every else looks like they do on the photos. The bottoms of the plants appear ok, but the tops are fucked. When it originally started happening, it was only the the spot of a static fan, so I presumed it was something to do with the heat being put into one spot from the fan, but it slowly got worse, so I decided to turn off the fan and one of the lights in that area incase it was due to the heat, now it appears have spread as much as it has. I've had quite a few sucsessful grows using the exact method I've used this time. Used the same feed schedule (4 times a day for 20 mins at this flower week). I've been averaging 6-7 ounces per plant. I'm pretty sure this one is screwed but looking for damage limitation and to correct any errors this time.