nuteburn, lightburn, or windburn?

600w light plants is around 7 inches from it. i am using a euro 6 inline fan cooled hood. plant is also on the oposite side of the hood the bulb is on. i had a fan blowing directly at the top of the plant, and also on two leaves on the top of the plant are showing this.
im highly doubting this is any kind of deficiency or caused by over fertilization. but would really like to know if you think it is light/heat burn or windburn. my temps are never above 82.

Its from being to close to the bulb. The leaf curling upward is a sign of heat and not nute issues.

thank you thats what i though. i realy couldnt find much info on wind burn and the fan was blowing directly on them. it might have been a combination of forces with the fan drying them out the heat from the bulb was able to penetrate more.

lovemug said:

thank you thats what i though. i realy couldnt find much info on wind burn and the fan was blowing directly on them. it might have been a combination of forces with the fan drying them out the heat from the bulb was able to penetrate more.

Click to expand...

IDK about windburn...a 600w should be like 16-20 inches away from tops of plants.

i just fought this same battle for about 2 weeks. I use a 400W MH and with my air conditioner in the room i was able to keep the lights about 4 inches above the plant witnh no heat problems. leaves started cupping and tips curling upwards. It confused the hell out of me because you hear so many people saying that there is no such thing as too much light. Pull your light back a little and they will bounce back. IME some of the effected leaves may stay surled like that but new growth will be just fine.

I don't think it's windburn, but I'd still remove the fan. Cannabis is a tough plant and when it starts showing signs of stress, you can count on more than a single source. Direct wind on the plants forces unnecessary transpiration, it's kind of like making the ladies do pushups. I prefer to pamper my girls like Kobe beef! Another consideration with fans is accidental pollination from stealthy hermie flowers. No fan, no problem. I'm not sure where the myth of direct fans got started (J. Cervantes?), but I've convinced hundreds of growers in the last decade or so to ditch those fans.

not sold with out fans temps r 5- 10 degrees diff. plus more air more c02 more buds