leave curl a few weeks into flower

I cant figure out whats wrong, when my plants are vegging under my t5's they are nice and perky, a few weeks after I put them into my flower room under a hps they start too droop and some of the leaves curl like taco shells, some curl up and some down at the tips. The only thing different in the rooms is the night time temp is much lower in the flower room. I run vertical 600's, I use fox farms nute, no co2. My medium is peat moss 70% perlite 20% vermiculite 10%. Humidity is 50%
Temp 54F night/ 67F day.

I had the same problem. I bought a plug in heater and have it running at night. So my temp at night is 55-60 and lights on its 73. Before the heater my temp with lights off was in the 30-40s. My plants look healthy now and are no longer curling. I hope this helps

The only thing is different is that its under a HIGH PRESSURE Sodium bulb , much different from the t5 you had them under. Leaves tacoing is usually from too much heat , the temp in your room has nothing to do with the temps near the tops of the plant closest to the bulb thats where you should chek your temps. Your temps should be higher than 67 lights on , where do you check your temp? Good Luck hope I helped.


Happy Growing!

I absolutely agree. Anytime I've experienced leaf curling as you've described it has been caused by the heat of my HID bulbs. The lamp may be positioned far enough from the plants to prevent burning them, but the radiant heat will certainly dry out the leaves
quickly. Also make sure you're not blowing fans directly on your plants as this will aid in the evaporation of your plants moisture.

my room is real cool right now even when the light is on. Its in the basement in a northern climate, with my cool tube i can put my hand right on it and its barely warm. Got a 400cpm inline. I temp gage is on the wall and shows highs and lows, been no lower than 53.

Ya I agree, it may be the difference between day and night temps and the HPS heating it up quick when powered on....

im 100% sure it is not a heat issue, like dude said nothing is really changing except hps, im stumped, im getting ok yields and good strong buds, maybe the change in bloom nutes IDK

its not a heat issue....once soil temps go in to 50's roots cant absorb certian nutes..im currently resolving this issue by building a insullated floor to put my 5x5x7 tent on...tent is on concrete floor of garage...i placed my hand on the tent floor(2layers b4 concact to concrete)and it was ice cold...so ive built a frame so far and gotta go to homedepot for rest of material tomorrow...

ahh maybe to floor is too cold

I just checked my runoff ph 4.5, I use soilless mix peat moss and perlite, I guess I better read and learn how to adjust