leafs curling down

im growing a few white widows at the minute and for the last couple weeks the leafs in the middle are curling at the tip down,ive tryed moving the light up and keep checking the temp but with no hope,could anyone help me out please.

i had the same problem last grow near the end. made no diverence to yeild quality some said its drastic changes in temp. is your ventalation O.K good circulation of air. it should'nt be a major problem

yer got good circulation just thought it mite be bad cuz this white widow spose to be a good smoke

My leaves are curling down at the tips as well. what is the reason for this. my plants are looking fucking sad and im starting to worry becuz it seems like they could be possiably dieing soon. If anybody has some help with this its appreciated, and if u need to see some pictures i will put some up on here

sound like a lil nutrient defficiency. try adding some phosphorus and potassium.