I had to end up getting a small humidifier for my grow. During the summer especially, mine just drops. The AC and Heat in your home is also a DE humidifier, keep that in mind. So having to run the AC all the time to keep the house cool and that room cool enough to grow, and I had a fan pulling air from the vent to the intake of the tent, that caused me to have low RH. I ended up putting that little humidifier in the damn tent and still couldn't get it as high as I wanted.
BUT, I did buy a small cheaper one. A bigger better one would do the job easily.

That mister could work fine though.