leaf and stem symptoms. possible diagnosis?

If i had a marijuana plant that had the symptoms of leaves curling around the edges and a few purple or dark colored stems but no yellowing or any other symptoms what could be the prproblem. Cfl setup 6 bulbs 122 actual watts total organic soil and nutrients fed once a week 3gal pot only 2 gal of soil vegged 3 wks started flower 4 days ago no sex yet. Loud bagseed.

Heat stress probably. Looks like it's almost 80f in your pic. My plants don't like temps above 78

Yeah my temp varies from 75 to 80 throughout the daytime but its been that since i germinated. So i was iffy as to if it was heat stress. If i lower temps will the leaves go back to normal? As long as that is the issue.

Sometimes they recover if you fix it fast enough but most of mine never recovered lol I've manifolded all my plants so they get chopped off anyways if it happens early on

If you cannot cool the space can you at least add more airflow?