I follow VPD @ high temps and humidity (30c and up to 75% RH) until the last few weeks of flower, where one instance of bud rot was enough to make me drop back to 24c @ 40-50% And even down to 30% during those stages where the buds are very dense. I don’t notice any difference in yield, and I think (and have read) that the lower humidity emphasizes trichome size.
The strains I grow are Sativa dominant and don’t mind the heat.
I also grow in Canada and do not use AC, only dehuey/humidifier, ventilation, and heat as my environmental control variables. I keep thinking about adding A/C but then finding other things to buy.
That is all lights on. For lights off I keep temp anywhere above 70c and humidity same as lights on target. I don’t care that much about lights off as long as humidity is relatively low and temp is high enough to keep dew point at bay...
I don’t ever stop any fans.
