Please see the 2 photos marked in the diary. Is t...

Looks like your very close to harvest. Typically growers will taper off their nutrients during the last couple of weeks then start a flush out of habit. The reason for this is plants tend to slow down or almost stop feeding during the last few weeks of the ripening stage. It looks like it could be PK burn do to this fact. A good way to check is to do a flush on the pots and see what the initial run off ppms are that first come out of the pot. if you have some crazy high ppms this may have been the issue. Another possibility is also light burn I notice in your photo that these plants are pretty much directly under the center of a 1000 watt light at 16". Hid lights emit infra red light so it can heat up the leaf surface. So I would perform a pre harvest flush and cut off all nutrients on them and back off your light. https://www.blackdogled.com/lst I would wet trim those buds and cut off any discolored sugar leaves they will clean up nicely. Hope this helps👍