It depends on the chameleon, and on the age and terrarium size. i have 2 mistkings, 1 for juviniles and crested geckos, and one for adults which are in very large cages (2X4X6). the juvies have mists every 4 hours during day, the first and last are 1 minute long, and the rest are 45 secs long. during the night i give them 2 mistings for 30 secs to maintain humidity and it does give them some morning droplets. The adults get a 5 minute spray for first and last sprays of the day, the rest are 4 minute sprays every 3 hours, and during night every 5 hours for 1 minute. It all depends on the chameleon and their drinking habits, my adult male has had problems with hydration and just refuses to drink off leaves and drippers, only drinks during the mist, so i give long adult mistings, and his cage has extra nozzles. It also has to do with climate, in toronto its dry from september to april, so i need to keep it up, the rest of those monthes are hot and humid.