20 gallon is far to large for a baby. Buy a medium critter keeper and place a UTH(Under Tank Heater) on the side thay is made for Hermit Crab enclosures. These frogs tend to become overwhelmed by large open spaces. They do best in small enclosures as babies. Cover 3 sides of the keeper witha natural background.

Temps for babies should be 80° to 82° during the day and 78° at night. Humidity needs to be 75% to 80%.

This should help.