The closer you put the humidity monitor to your pots, (which contain moist soil) the higher the humnidity readings will be. Just like taking temperatures under the light will read higher temperatures. I guess what I'm saying...is make sure you are not adjusting a skewed reading. What are the humidity readings on the other side of the closet/room?

I'm not a believer in foliar feeding. In flower, I keep the humidity as low as it will go, and I never spray 'em unless it's to correct deficiencies. (heat and moisture can quickly cause mold) During monsoon season when humidity levels jump, (50% RH and up) I put the circulating fans on a higher setting in an attempt to keep leaf surface 'drier'.

Higher humidity and colder temperatures lower the dew point, which is the point moisture (water vapor) starts to collect on surfaces. (again...a potential mold issue)