Horn frogs are cute, been toying with the idea of getting one myself. Like I need another animal
. From what research I have done they seem to be fairly tolerant creatures. 60-75% sounds okay for humidity, I personally feel like 75-85% is a good range. As long as the frog has a water area that it can soak in, it should be fine. Also using a moistened mossy type substrate will help keep humidity up if you find you're having problems. As far as feeding goes, in nature these guys are ambush predators. They sit in one spot for days waiting for something tasty to come by and WHAM! So in captivity when you're feeding them daily they can have issues with obesity. After all they're eating at a buffet and not expending much energy. So either feed a few items daily or feed more/bigger items every 2-3 days. And don't forget to dust
. Hope that helps you some, enjoy that cutie.
Dan