Yeah, i've been battling very high humidity all summer (67%-88%....75% average).

I have 2 oscillating fans moving some serious air and my shitty exhaust system is on 24/7. I haven't had any mold problems yet and i've made it through 3 harvests this way.

i'm going to be getting a dehumidifier and upgrading my ventilation after this next harvest (probably next week). My yields are decent...but i can't help but think they'd be a bit beefier and more crystals if they could breath a little easier.

so it can be done...just keep air moving like mad...make sure the plants aren't touching any walls and have plenty of space to move the air around them...and keep a check for mold. oh. and keep your room CLEAN.

As far as a difference between night and day humidity...i find that when the lights are off the humidity tends to rise. Stinky thought maybe i was getting a bit of dew fall...so maybe that's the explanation...

although the best option would be to improve the RH%. Believe me...i know how much it sucks to have to buy expensive and power hungry equipment to fix a simple problem.

Skeet.