looping top leaves (never seen this before)

burrr said:

I believe it's nitrogen claw. Heat stress curls up, and rolls edges up.

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Burr I don't think its nitrogen claw as I've grown the same strain and my nutes had double the nitrogen in them and mine just soaked it up. I never got the claw.
Cheers for you input though.

over watered-

and beginning of to much N. lower leaves have clear nute burn on margins.

remember that it's important to control your humidity.

Let me put a question to you all.....?

If the lights off period was interrupted by the light coming on for any period could this cause what's happening because to be honest I don't believe the lights are doing this as they have had previous grows in the same room in summer with higher temps with the same lights with no problems.
As for the nitrogen thing I can't understand how this could be possible as upto 14days into flower the plants looked great and the nitrogen content of the nutes is low and these are only fed for 3 days before being fed a Day of plain water.

Cheers all