m0useanswered grow question a year ago Place a bowel of water in the tent with a towel dipped into it, then if you want, the fan blowing on the towel.
The fabric will wick up the water and raise RH all on its own, if its still not enough have the fan blow on it, this will increase the surface area vs just the water alone in a bowel plus the fan will encourage more liquid to be wicked up by the towel as its drying/evaporating faster. you ideal RH is aorund 60-65%
Good Luck!