if you get one of those big storage containers and put bubble wands in the bottom and hook the bubble wands to an aquarium fish tank pump, then fill the storage container about 6 in. with Hydroton/ Geolite, or perlite and then fill it with water and a little iodine(to kill microorganisms) it produces alot of humidity. it's what alot of people do to grow mushrooms. the perlite, or hydroton/geolite is highly porus, and as the air bubbles go through the water and porus substance humidity is created, it's alot cheaqper than buying a cool air humidifier, and it dosent get as hot as the steam humidifiers.