Why Are the Leaves Curling Upward?

These are about a month into vegging, using a continuous flow system. I havent had any problems until now. The leaves (mainly at the top of the plants) are curling upward. Could this be due to heat stress? Or is is a nutrient deficiency? I'm using nutrients from a local grow store, and I havent any problems until now, so I don't see why those would be the problem. The temp ranges from 70F to 84F with a humidity ranging from 55% to 60%. The pH is around 6.0 with freshly changed water. Please check out the pics and let me know what you think

Where is the temp meter in your room??,place it on top of the canopy and see what your temps are then.Leafs curl up in attempts to cool themselves down.

Could be PH issues too, try to keep the PH at around 5.8 for best results.

Looks like heat stress, have you got a fan in there?

It definitely looks like heat stress. Try improving ventilation or fans like suggested above! cannabis deals better with colder weather than hotter in my opinion and experience. Good luck! Also your plants do look extremely close to the light. Remember some plants can grow up to 3in + in one day so be careful and good luck once again!

deviantboi said:

It definitely looks like heat stress. Try improving ventilation or fans like suggested above! cannabis deals better with colder weather than hotter in my opinion and experience. Good luck! Also your plants do look extremely close to the light. Remember some plants can grow up to 3in + in one day so be careful and good luck once again!

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Yup it is Heat stress .. Get that air moving around.. ventilate the air.. and temps should be at 72-78 degrees..

your temps dont have to be that low. thats just recommended. if you think about it some of the best green is grown in very warm places outside where temps are in the 90's just about every day. just keep the air moving and do what you can. 1 of my closets stays right around 85-92 with a 45% humidity and my plant and clones in there are doing just fine. im guessing your hotter then 92 how ever. when my closet was getting up to 102ish my leaves did that. so just try to drop the temps abit. throw some PC fans on the side of the box to get fresh air in. and a bigger fan at the top for exhaust. if u dont want to add pc fans on the bottom just get a large enough exhaust fan to create a passive intake.

By the pictures it looks like there are no fans or any type of ventilation.. those are a must. they need to have fresh air.

Thank you for all of your responses. Well, when I moved the temp meter to the top of the canopy it was definitely 100F ( I don't know why I didn't think about that). I do have a fan for ventilation, and it lowered the temps significantly. However, I will definitely take your advice and add another fan on the bottom to push the air toward the ventilation fan. I also moved the plants to about 8 inches from the lights, and the temp at the top of the canopy is now 87F. Once I add the extra fan I think I'll be in good shape. Thanks again!