I know the problem is I have a 55 gallon tank, Can someone help me to figure a way to get my humidity up?

I've got most of the top covered with plexy glass except for where the heat lamp is and a crack on the cold side to provide ventilation. I also made a humdifier with a fish pump, a jar, and sponge. I also spray the tank on average of once a day. but I can't seem to get the humidity over 60%. Please help so I can get a good shed and our snake is more comfortable. I'll try pretty much anything