Unless you have a very big tank a 75W will just dry it out in very short order. I wouldn't go over 60W and I think you'd be better off using a thermostat-controlled heat mat so you get no light at night and some heat without the drying effect. If you wanted to view the frog at night you could still use a low wattage black or red bulb but instead of having it on all night just for a few hours. Many of my frogs have been disturbed with these lights and I've noticed big changes in activity when switching them off