leaf edges are tightly curled up... what's wrong?

I looked at lots of pics of nutrient deficiencies but didn't see anything that looked like this. What am I doing wrong?

I have one 400W HPS and 1 400W Metal Halide bulb. The plants are on 18/6 light cycle. The room is averaging 25 degrees Celcius (77 Fahrenheit) although occassionally it is hot outside and the room goes up near 30 (86 F).

heat stress. raise your lights or lower your temp.

^^i would say so too fdd but its odd that it starts already at 86F, he must have those laps damn low

to-ka said:

I looked at lots of pics of nutrient deficiencies but didn't see anything that looked like this. What am I doing wrong?

I have one 400W HPS and 1 400W Metal Halide bulb. The plants are on 18/6 light cycle. The room is averaging 25 degrees Celcius (77 Fahrenheit) although occassionally it is hot outside and the room goes up near 30 (86 F).

Click to expand...

is this tinfoil in your pic?! if so kick it out of your grow, tin foil only gives you hot spots. if this is mylar get it crinkle free and flat to the walls. the best to go with is anyway plain white non-glossy paint, so you may try this.

i'm having this problem. i have my thermometer IN my garden. right in the middle under the center of the light. my temp gets up to the low 80s with CO2. i still get leaf curl heat stress. it could be a transition from flors to HPS on my plants. or maybe it's the strain because some show it and some don't. i don't know. my buds were getting strecthed out. i now keep my temp at mid 70s. it has stopped.

to-ka said:

I looked at lots of pics of nutrient deficiencies but didn't see anything that looked like this. What am I doing wrong?

I have one 400W HPS and 1 400W Metal Halide bulb. The plants are on 18/6 light cycle. The room is averaging 25 degrees Celcius (77 Fahrenheit) although occassionally it is hot outside and the room goes up near 30 (86 F).

Click to expand...

funny how u asked what was wrong, but in the same post U made mention of how hot it gets, you must know or at least have a feeling that the curling is due to heat stress or light stress. some plants like to be further away from the light source, or in indirect lighting...you've got 2 HID's running? I say lose one for now, Im pretty sure you dont need the red spectrum from the HPS right now. not only will it cut down on the heat and direct light, but the light bill will decrease too.