During flower, you will want to be below 55%RH or so. Run a beefy exhaust at night, too, to prevent dewfall and also stabilize the night/day temperature swing.
Is ambient outdoor humidity high, or are you getting high %RH numbers for reasons within your space, which you might be able to improve?
stinkyattic Reviewed by stinkyattic on . High Humidity The humidity of the non grow area is 50% which is an a/c environment. Will humidity in a gow room in the range of 65% - 75% with fans constantly blowing cause a mold problem? Will this be ore of a problemo at night or also during the day with ladies reaching for the HID's? A dehumidifier is an option but it takes a lot of juice. Has anyone had a successful grow with this high level of humidity? Rating: 5