PATHOGENS....we been over this. You put them at increased risk of infection. You argued "what about rain outdoors" And i think you called me a fuckin idiot and a dummy as i recall. Well dude, you are growing INDOORS, not out in nature. Nature creates the perfect balance. In nature, plants get dirty with dust and debris from stuff blowing around in the air. A dirt road near by, a dry field, whatever. Inside you have none of that. What possible benefit do you think misting water on your leaves is gonna give them?
If you are gonna spray shit on your leaves, you mix a nutrient mix at the right pH and mist the undersides of your leaves where they actually absorb nutrients.
Thats the ONLY time it has any benefit. But it's a pain in the ass cuz you have to do it daily and you make a fuckin mess around your grow space with the inevitable spray that misses and goes everywhere. Back in the old days you have 1000w bulbs above and 1 micro drop on a bare bulb = BOOM, bye bye bulb.
Stop beating this question to death for fuck sakes you've been told again and again.