what is this??

phosphorus def??

Yeah looks like it id say.. either that or nute burn

can be heat stress??

Not heat stress, they wouldn't be slouched like that, they'd be canoe-d up

Cal-Mag Def.

That's the beginning of 'claw leaf' I get that problem a lot. It needs to be fixed otherwise the plant gets permanently sick.

In my experience claw leaf is caused by extremely low humidity (my problem) and exacerbated by too much heat and too much nutes. These things go together, once the leaf is affected, its transpiration rate goes down and with it it's ability to cool itself by evaporation making the problem even worse. Over nuting or ph problems, which might not really be a problem normally further dehydrates the plant. I agree you seem to have overnuting as well.

My solution is flush her heavily with distilled or properly ph'd water. Spray the leaves, cover her with a humidity dome of some sort ( clear plastic cup, half a soda bottle, saran wrap and stakes ... ) and put her away from the light. Mist under the dome several times a day.

With this therapy mine usually recover in a day or two but remain susceptible to this problem for some time. When I see any sign of it reappearing, she gets misted and covered again.


Good luck

i strongly flushed a week ago (they recovered), but now you say that and what a coincidence, my humidity it is about 20% and the temp 35° celcius (but i got a veeery good air flow inside the closet), do you think its a good idea spray them strongly? and also put water cups inside? otherwise i dont know how to rise humidity.. may be a very wet towel inside

edited: they are more than one month flowering.

Yeah 20% is what I get too. It's hard to fight. The only thing that makes a difference in my cab is a mini evaporative cooler. Air flow is a good thing but it also has a dehydrating effect. The mature plants are less bothered but the young plants can get into serious trouble.

You need to do something about the heat. 35C is 95F which is simply waaaay too hot for the plants to be happy. About 25F is what you want (if I did the conversion right).

The heat and the dryness together are a fierce combination.

I have tried flushing alone but I have not had a plant recover from claw leaf without at least misting and covering as well. Misting alone wont do it and a dome alone wont do it. Also, absolutely no nutes for a while.

I suggest you put the fans on a timer and dont run them all day.

I just keep a collection of paper cups etc for humidity domes and cover any plant that shows the first sign of clawing.

For sick plants I actually wet down the leaves once a day but you cant put her under a strong light with water droplets on. For the others I just spray the inside surface of the dome.

It's not severe in your plant but if it goes on too long, the roots start to get sick too and I've never brought one back from that state.