Originally Posted by Zandor
50% is fine for most people. If you have AC and a closed room with CO² then more RH is great.
As you finish the last few weeks you need to get it down too that is to high for flower. To finish you should be aroud 25% - 30% and that will keep mold from getting a hold.
You need to have plenty of fresh air moving around your plants at all times.
But I would say you lower then expected yield may be something else.
What nutrients are you feeding them?
What supplements are you using?
What type of water?
How long do you veg them before you switch to 12/12?
What type of lights are you using?
You may want to check out my show if you are having problems the odds are in your favor that I already address most of your questions.