The humidifier is from Taotronics, I also got it off Amazon but it was $70..I probably could of found it cheaper but I needed it asap and it had the 2 day Prime option so I went for it..I use distilled water in it and can get by on a gallon for about 4-5 days with the low mist setting and the humistat set on 70% ( The humistat goes up to 95%) The humidifier kicks on automatically when the humidity drops below my desired setting..With my current weather situation,the extraction fan off, and the tent zipped all the way up except for a little opening at the bottom, my tent levels off at a nice 66% rh..Temps peak sometimes to about 80 but no further..The box says between 66-82 cubic feet..4 Liter tank