Quote Originally Posted by razzapiggy
Okay, so it's time to get a d/h ASAP. My lights off temps have leveled out at 61 degrees Farenheit and SEVENTY SIX percent relative humidity. I have no clue how this is possible. Can someone explain to me how lights on my r/h is getting down to as low as 43%, and then the lights go off, temps drop about 9 degrees, and it goes up as much as 33%? That's fucking nuts.
The lower the temperature of the air, the more water vapor it can hold. So when your lights turn off and your temp goes down, the air floating around your grow room becomes a better vehicle for H2O. Water gets "burned" out of the hot air, so that's why you get the huge variation in R/H in 12/12.

Before I got a D/H, I was getting 60 percent humidity with the lights on and 95 percent with the lights off. :wtf: Of course this only lasted a few days.