Three words pretty much cover the market when you're talking about housing for amphibians, and those words are “cool,” “clean” and “damp.” Amphibians breathe partially through their skin and mucous membranes, both of which need to be damp or moist in order to be permeable. And an amphibian's surroundings must be kept clean so it doesn't absorb waste products through its skin.
You have two choices when it comes to housing your amphibians. It can be either simple or realistic. The simple housing works for many species, such as horned frogs. It just takes a shoebox or a deli cup lined with a damp paper towel. Obviously, this type of housing is easy to clean; but a deli cup doesn't have much visual appeal, and this kind of housing certainly won't result in natural behavior on the part of the amphibian.
Comparatively speaking, the realistic environments are more trouble, both to set up and to maintain, but their eye-appeal, as well as what many hobbyists consider the obligation of keeping any captive animal under the most optimum and humane conditions, may persuade you to put in the effort.
Natural environments for amphibians depend on the species being housed and can range from aquatic to terrestrial to semi-aquatic. Terrestrial species, like many salamanders, tree frogs and woodland frogs, need a terrestrial tank. Aquatic amphibians, like the clawed frogs, waterdogs and Suriname toads, need an aquatic tank, while marsh and meadow frogs like leopard frogs do best in a semi-aquatic tank.
Housing for Terrestrial Amphibians
A terrestrial tank can be either horizontal or vertical in format. Salamanders and woodland frogs are more at home in a horizontal format. For climbing species, like tree frogs, use a vertical format tank.
The terrestrial tank begins with a base substrate of an inch or so of river rock. Cover the gravel with one or two layers of plastic screening, then add dampened sphagnum moss, potting soil or mulch for another inch or two. (Avoid cedar mulch; those tantalizing cedar fumes are lethal to amphibians and reptiles.) Bury a few potted plants like pothos to their pot-edges in the soil or mulch and add small pieces of cork bark as hiding areas.
Tip the cork bark pieces so viewers can see under them, or place them against the glass. A small, shallow water dish will provide a watery “sitting” area and will provide insurance against the tank's inadvertent drying. Add a tank light with a 15- to 25-watt bulb to provide diffused light without heat.
For tree frogs, set the tank on one end so it offers a taller climbing area and add a network of climbing branches at least two-thirds the width of the frog's body. If the tank cannot be set up on one end to provide a taller cage, at least add the climbing branches and plants so the tree frog can climb up over the substrate.
Housing for Aquatic Amphibians
An aquatic tank is essentially an aquarium, just like you'd set up for tropical fish. You'll need gravel for the substrate, a few floating plants to serve as a surface resting area for the tank inhabitants, and a filter. Submersed powerheads with foam filters do a good job of keeping the tank clean, and the filters are easy to rinse clean.
Use a chloramine/chlorine removing agent to treat the water before you add any live animals; the additives that make tap water safe for you to drink can be rough on permeable-skinned creatures. A standard reflector top will provide lighting for the plants, but be sure to cover any openings around air hoses or external filters. Clawed frogs are escape artists and will wriggle through amazingly small openings.
Housing for Semi-Aquatic Amphibians
A semi-aquatic tank, which is roughly half land and half water, will provide environments for both terrestrial and aquatic amphibians. You'll need to install a barricade to keep the water and land area separate. Use silicone aquarium cement and a segment of tank divider or a piece of Plexiglas to wall off about half of the tank, about a third to a quarter the height of the tank.
For the land area, add enough river rock or gravel on the “land side” of the barricade to fill the space to within two inches of the divider top. Cut a few layers of plastic screening to the shape of the land area and place over the gravel. Then add dampened sphagnum moss, potting soil or mulch to the top of the divider. You can also add a few small potted plants to the land area.
Add a corkbark hiding area, tilted up at the front or wedged against the glass so the salamander or newt hiding beneath can still be seen. Again, add a small fluorescent or incandescent light so the plants will live. You don't usually need to worry about having to add the warmth provided by an incandescent light. Ambient temperatures of 70 to 75 degrees Fahrenheit for both the water and the land area will suit temperate amphibians admirably. Tropical species will need temperatures of 80 to 85 degrees Farenheit.
Add gravel or river rock substrate to the flooring of the water area, and then add water to the top of the divider. Fill the water area to within a quarter-inch of the top of the barricade to make access and exit easy for the inhabitants. Rooted or floating plants can be added to the water area.
Plan to change the water every two weeks and to change the land area every other month or so. If space permits, you can add a submersible filter to the water area to cut down on your cleaning time. An external filter works as well and take less tank space if you're working with a tank that's 20 gallons or less in size.
If you're keeping small amphibians like dart frogs, a semi-aquatic tank can be set up without using a water/land barricade. Use gravel as your base material and slope it up on one end to create a land area that will take up about half of the tank. Add a layer of sphagnum moss atop the new land area, position your potted plants in the moss, and you're done.
To clean, you set up a siphon in the water area (or take out the plug, if your tank has a plug in the bottom), and pour two to three gallons of clean water through the sphagnum. Detritus will be flushed from the land area into the water area, and all the dirty water will be sucked up through the siphon. Remove the siphon (or replace the plug) and add fresh water.