When I kept my sallys, I used a screen top with glass panes and had my fluorescent light to one side unblocked by the glass. I also had a bubbling water dish within the aquarium and a hygrometer/thermometer to check temp and humidity. I would usually mist in the AM and give the tank time to evaporate that. I would add or remove the glass depending on the heat of my room. Seemed to work out fine. I definitely like the 'open top' approach.