Copper has always worked for me but after reading that its a heavy metal an builds up in soil I have changed over to sulfur this yr zero black spot an zero pm. The trick is to recognize it early an start treatments.
Looks like downy mildew aka stem rot might want to remove that plant once its in a plant it moves around fast. I do not know of a cure just some preventives.
Just run the exhaust back into the basement with lights out to recirculate the air, no need to exhaust out the building with lights out unless it gets to hot.
I haven't sprayed any thing yet other than sulfur Iam just starting to see cats now soon as it stops raining Iam spraying Spinosad tonight when I put cover on the plants i go to Bt that will be 3-4 weeks.
What you really need is a dehumidify run it when lights are off along with the exhaust it will warm things up an keep things nice an dry in the whole basement.
Its a perfect time to clean up all that lower stuff 1-2 ft an some of the inner stuff to increase air flow, I wouldn't touch the tops at this point. You do have something funky going on plants dont look 100% healthy.
Pic# 6 on post 86 looks like witchs broom to me I have had it a few times over the yrs is that stem at the top kind of flat ovel instead of round like normal. Just look for purpling or black leaf on the very top in the next few weeks to know for sure.