A humidifier needs a filter, yes, and the water level goes down - mine takes 3 gallons of water or more in 24 hours. I do believe you have a vaporizer, not a humidifier, and if you bought it used, it could have mold in it. Wal-Mart sells brand new vaporizers for as little as $9 (I got a Vicks vaporizer there for that price) and a humidifier can be bought for a small room up to one that does a whole house, mine does up to 800sq ft and I paid $37 for it at Menards. What you need depends if you just want to humidify your whole house, or if you have a sick child. If you have a vaporizer, it's not meant to humidify the house, but to help a sick child. A humidifier is not "supposed to" help a sick child, unless of course it's a dry house making the child sick.
at 1:55 PM on Dec. 9, 2009