Say No, The most important reason for fans is circulation. You have to move the oxygen off the leaves to get more co2 in. It does make for stronger plants but mine are plenty thick now. I wonder if plant stems get thicker at night? That would be a good reason for 24/7 if your plants were skinny.Well if electricity is a real problem then you could run them on a timer or something. All it does is build it stronger.
Perfect, I put my oscillating fan on a timer for 12 hours, my heater/fan combo turns on at 60F. That runs all night this time of year. I wish I could find a fan/heater combo where the fan could be on 24/7 while the heater went on at 60F.It also helps with keeping good air circulation in your grow space, prevention of pathogens, mould etc etc.
There are plenty of reasons to leave them on.There are no reasons to turn them off.
No, didn't say that, strong plants are important. Circulation is always important.so you think the fans can stay off as long as the plants arent weak and thin?