When i used tanks a good trick i was doing was instead of misting the bedding i would mist the walls inside the enclosure and i would only have to do this twice a day to keep the humidity at about 50% also i had a decent sized ceramic dish right on top of the heat source. Also (just throwing this out there) with the right sized heat mat or flexwatt and a tstat you can keep temps up to par without a heat lamp. Duct tape the screen top and leave about 1/3 of it untaped and you should be good.