Hi Rad. Looks like things are still cooking very nicely.
As far as your night time flowering temps go, I think it probably has a lot to do with the particular strain you’re growing. My WW grow (of which I did a final harvest today), had similar conditions to yours. Under CFL, daytime temps were in the 75 degree range, and dropped to 63 at night. I read extensively on WW before choosing it and some have suggested that it is a more cool-weather strain that does ok at night down to about 60 degrees. It is a European strain. We could find some tropical zone strain and that likely wouldn’t work well at all like that.
Since you have several strains going at once, it’s probably best to shoot for an average temperature range, and the heater seems like the most likely direction to go so that you don’t get too moist.
(pun intended) Maybe not as high as 70, but at least in the upper 60's
I’m about to move my 3 AKs into the main grow area that’s currently being cleaned and prepped, and they’ll likely get the same temperature treatment as my first grow. I don’t have any solid data on AKs nor their temperature preference, though I’m not about to go spending a ton of cash on running a heater on top of everything else unless I find some sort of consensus on what type of strain it is and that it might make a big difference. We’ll see how it goes, and what I learn between now and next week.
Did you ever make a “heat transfer” window between the two spaces?