Should fans be on all day

Should you keep strong fans on all day? Even when lights are out?

Mine are on 24, but never on high?

I would, as it helps blow insects off the plants, as well as promotes thicker stalks.

As long as they get SOME airflow each day.

Yes air movment is good. EXP because when a plant is swayed in the wind, the stress causes the plant to release auxin wich is essential for cell development.