well most of the time it won't stay at 100% or you could just run a dehumidifier it bring it down a little, but I've never had any problems and mine is 85%+
but I do get what your saying now.
At 75% and over i start to find things get damp and with extraction thats the inside of the tent and the room my tent is in, any humidity at this level is going to start culturing bacteria and fungi as it does in some damp houses.
After years of trying every humidity, vapour pressure deficiet and temperature combinations i find that the easiest and best humidity for seedlings, veg and flower is around 50% all the way through.
At 85% you probably need higher temps to achieve transpiration but im not wanting to get into it, suffice to say as long as its not too high or low all plants should grow. At 100% im probably waking up to a tent of fog and here in the UK 50% is about average for the year, slightly lower in winter and slightly higher in summer.
I have a kick ass digi humidifier but i gave up bothering as my tent stays above 30% and below 75% and no ill effect on plants or seedlings.
My apologies for being rude but i wasnt sure why this thread has gained any kind of response, i posted on it five years ago which is why i got notified that someone had posted on it recently and hence my post
Dude... why are you posting on a five year old thread? Do i know you?