humidity problem

I am growing in my basement in a small stealth box. The humidity is around 30%. My question is, how do I get more humidity in this little hidden box?

Humidifer at wal-mart.

one thing you can do is freeze water bottles and put one or two in your grow box....the condensation when the ice melts will raise humidity. I have done this several times. Are you running fans? higher heat eaquals lower humidity and vise versa. It's kind of trial and error getting the right equation but hell.....I figured it out so it cant be too hard. good luck

I used to put 2 litter frozen Ice bottles in my res. never helped my humidity. If you get a humidifier make sure it is cool mist, especially if heat is a problem. But I do agree if your running a exhaust you will have a hard time getting hum. to raise. Next if you are running a fresh air in fan your at the whim of the air coming inside. I've grown killer WW with humidity lower than that though but changing hum. can be a pain. I always worried more about too much at harvest.

30% is fine.

Depending on what phase of growth you are in, I have noticed the humidity rise during flowering. If you are vegging, I think the plants thrive in 45-65% humidity. I would save my money on a humidifier, and put some cups of water, or frozen bottles as already stated.

thanks, i'll give it a try