If you're looking to buy a frog as a pet, there is one very important question you have to ask before you determine the appropriate habitat: What kind of frog do you want? Some frogs, like the bullfrog, like dry environments. Dwarf pipids, on the other hand, need an aquatic tank. As long as you ask this important question, you will be able to determine exactly what your frog needs to be happy.
Dry Region Frogs
Dry region frogs are probably the easiest type of frog to take care of since they need very little water. This eliminates the hassle of having to clean out an aquatic tank on a regular basis. First, you will need to purchase a large terrestrial tank. The smallest size you should purchase is 20 gallons, but a tank up to 70 gallons is optimal for a species such as the bullfrog. Sand is a suitable liner for this type of habitat.
Other important aquarium necessities include a water bowl for your frog to drink out of or hop into and a small enclosed area to provide some shade. The latter requirement can easily be accomplished by purchasing one of many decorations commonly found in pet stores. The classic shading accessory for frog aquariums is the hollow half log.
Aquatic frogs need exactly what you think they need--water. Luckily, aquatic frogs generally only need the same type of environment that fish need in an aquarium. Use pebbles as a lining, add an enclosed area so your frog can seek shelter and include a few plants. The tank should have a filtration system and have a capacity of at least 20 gallons.
Semi-aquatic frogs need both dry land and water. Semi-aquatic frogs are the most popular type of frogs, so there are plenty of examples of the habitat they need to survive in. First, you need to purchase an aquatic aquarium (at least 20 gallons) with a filtration system. Next, half of the aquarium must be filled with something to act as a land mass. Bricks or even building your own small platform will suffice if you do not buy an aquarium with a land mass already built in. Finally, fill up the aquarium on the side without the platform and fill it up right before the water reaches the top of the platform. This will keep the top of the platform dry but keep the water high enough so your frog can easily jump in and out of the water from the platform. The only other thing your frog will needs is an enclosed area to hide in.
Tree frogs need the most complex aquarium setup since they spend most of their time in trees. First, you need to purchase an arboreal aquarium. This type of aquarium is usually hexagonal in shape and much taller than it is wide. This design allows for taller plants to be placed inside. Line the bottom of the aquarium with moss or some other plant-like material and place at least two tree-like plants inside for your tree frog to climb. Place a water bowl inside the aquarium.