FWIW, my grow is a little over a week into flower, and it looks like it may be just starting to stretch. I'm growing 4 plants in coco coir, and about a week ago they just started touching the walls of the tent, about when I flipped from 18 hours to 12 hours of light.
Being in coco and getting fed every 2 hours, the plants are growing like monsters. I've been doing a little pruning of the undergrowth, and I take leaves from the large plants trying to overgrow into the smaller ones. I'd previously topped each plant twice.
During veg I added a humidifier and set humidity to 70%. AC Infinity fan set to go full speed around 80F, and with light on, temp usually 83-85f, humidity 67-70%. Air coming into tent is whatever it is in my house in Phoenix, AZ, which is to say it is pretty dry.
And then the lights go out. Temps drop to an amazing 65F (house is set to 76F), and humidity goes as high as 88%. Leaves are dripping a bit of water where they touch each other.
In the past I've added another vent fan running full time. I've also pruned undergrowth to get better flow. My last two coco crops did this as well.
Overall, I like the temp drop, and I worry a bit about molds and the like, so I'm trying to get the RH down to 60-65%. At this stage in the crop I don't need to add humidity.
I do have a small fan running under the canopy and a second small fan blowing on top of the canopy. I'm a bit surprised at the amount of RH spike at night, considering my 6 inch AC Infinity is running at 100% speed, dumping the tent air into the hallway outside the growing room (upstairs bedroom).
All that humidity is putting moisture on all the leaves, which act like evaporative cooling at night. As the plants stretch, and I continue to prune undergrowth, air flow will naturally increase and drop humidity, and turning my humidifier down during the day should also lower the RH at night, if it is running at all during the day. For sure, in the past week my humidifier has been using almost no water.
