Hooked leaves

I have 10 ak47 plants, growing in soil under a 600 watt hps light, Temp is 76-78 lights on, 70 lights off, Humidity is low, as i grow in the same room as a boiler. The problem im experiencing is the end of the middle fingered leaf on each plant is bending down, not curling just bending and its only on the middle finger of each leaf. I thik it may be due to the dry arid air. Ive been misting at lkights out each day, trying to raise the humidity. The clones are only two weeks old and apart fom the bending, look fantastic. Any ideas?

do your leaves look like it is clawing? Mine are doing the same thing..Some plants more than others..I think it might be an air humidity thing

They do look like there clawing, but not massively, and only the tip of the leaf. And only on a few of the plants When theres low humidity or dry air, you usually get the single, long fingered leaf protruding out. Its not as serious as this yet, but there going into flower in the next few days, need this sorted out.

is the very tip of the leaf a slightly lighter color than the rest of the leaf? if so it may be too much nitrogen. what stage are you in (veg? flower?) and what nutes are you using?

" weeks into veg, no nutrients at all. However I am watering a less more often to try and raise the humidity a bit, this may be releasing the nutrients already in the soil too quickly? possible? I dont know.

and when was the last time you had your boiler serviced? all boilers emit a bit of carbon monoxide but a poorly tuned one will emit alot more.