How can I keep the humidity up in my new 10 gallon viv? I spray it in the morning for 60 seconds and it usually reaches 80% but by afternoon it's back down to 60%. I don't know what the problem is. Half the top is covered in glass. The substrate retains moisture. 60% of the tank is water. I want to figure out how I can make it last longer because if I ever go away for a few days, none of the people I ask can spray the tank three times a day. Should I cover three quarters of the top with glass?