i usualy go with 5 gallon to an animal. so 3 would be 15 gallons, 5 would be a 25 gallon. temps will range unless you good at keeping a constant temperature. for me its been glass enclosures hold moisture in and the heat of the lights keeps it steady. temp normally is about 84 degree with a 75% humidity range. you dont need hieght as they are ground dwelling frogs. they will bredd rather easily if they arent stressed, and given the proper conditions to breed. you can add a waterfall if your creative enough but simple msiting will do the job. i have a 2.5 gallon pesticide sprayer, but its was bought brand new and used for clean water only, and i use it for misting the enclosures down. hope this helps.