Waterfalls and Drip Walls
Photo courtesy of Eric Hanson
Aesthetically, water features provide a visual display that enhances the appearance of a terrarium. They also help maintain high levels of humidity, which may be necessary for keeping many tropical amphibian species. Some people report water features help promote breeding activity in certain species as well. This article explains three basic techniques for creating waterfalls or drip walls in terraria that can be expanded upon or adapted to different enclosures depending on the situation.
Before putting together a water feature, it’s often helpful to plan first. Some hobbyists like to sketch the concept of a waterfall or drip wall before building it. Spend considerable time picking out what you want water to trickle down, but realize that water does not always go where you intend it to. The height of the enclosure is an important consideration. Waterfalls are best suited for terrariums that are at least 45 cm (18 in) tall. It can be difficult, and often not practical, to attempt to build water features in shorter terrariums.
Submersible aquarium pumps are what move water in the first two approaches described. These can be purchased from pet stores that have an aquarium department. The type of pump needed depends on how high your intended water feature will be. In the United States, gallons per hour (GPH) is most often used to rate pumps. Stronger pumps move more gallons per hour and are more powerful.
One way to create a water feature in a terrarium that I did not include in this article is purchasing a self-contained one from a pet store or terrarium supply company. These waterfalls are often the best way to provide moving water in simple setups or in temporary terrariums that won’t be setup for long periods of time. They do not look particularly natural however, and for this reason you might want to avoid them.
1. Using a submersible aquarium pump inside the terrarium
By placing an aquarium pump inside a terrarium under the drainage substrate, it’s possible to create a small water feature. This approach does not require drilling glass or having to think about concealing a pump outside of the enclosure. The downside to this type of setup is that accessing the pump is difficult. If the pump breaks or needs to be fixed, the animals in the cage need to be removed and the area under the waterfall needs to be disturbed. Before placing the pump in the drainage area, it may be helpful to wrap a piece of filter fiber over the intake so that it doesn’t become clogged with soil or small pieces of gravel. If you find the pump becomes clogged with debris, unplugging it so that the flow of water is reversed for a moment will often fix the problem.
In this style of water feature, a submersible pump sits under a false bottom. The false-bottom is modified so that the area directly above the pump can be removed to do maintenance on the pump if necessary. Large gravel can be used as a drainage area in place of a false-bottom if you prefer, but can make accessing the pump more difficult. Small pea gravel will become stuck in the intake of pumps and should not be used. A tube is attached to the output of the pump and runs up through the false-bottom, gravel, soil and up to the top of the rocks, wood, or whatever material you intend for the water to run down. The area where the water falls through the gravel and false-bottom is left free of soil so that the soil does not fall below and clog the pump.
2. Using a sump to house a submersible aquarium pump
Housing a pump outside of the terrarium makes accessing it easy. When maintenance has to be performed, simply reach under or beside the tank and into the sump. Two holes need to be drilled in the terrarium in order for this style of water feature to work. Glass can be drilled at most glass shops inexpensively. Often the glass shop will need you to remove the sides of the enclosure that needs to be drilled. This can be done with a razor blade and then resealed with silicone sealant. Many aquariums come standard with a tempered glass bottom. Tempered glass will shatter into many tiny pieces if it is drilled so make sure to find out if the glass used to create your terrarium is tempered or not. Generally, only especially large enclosures have a tempered glass bottom.
The concept behind this style of waterfall or drip wall is to use a separate container beneath or beside the aquarium to house the pump. A plastic bulkhead is attached to both of the holes in the terrarium. Plastic tubing is then attached from the bottom bulkhead to the sump so that water can flow (or drain if the sump is below the terrarium) into the sump. A second piece of tubing is attached to the output of the submersible pump and runs up out of the sump and to the top hole in the terrarium. Large gravel can be used instead of a false-bottom, but the area around the bottom hole will need to be sealed off with screen or a partial false-bottom so that soil and other debris doesn't clog the hole.
Using a sump that is level with the terrarium is the ideal way to do this. If the sump is level with the bottom of the terrarium you don’t have to worry about the water draining faster or slower than it flows from the output of the pump. If the sump is placed under the terrarium it can take a while to play around with the settings on the pump to figure out how fast the water should be pumped so that the sump doesn’t overflow or run dry. It also can take a while to find out how much water should be placed into the terrarium so that the sump does not overflow. The use of a check valve may be helpful to prevent water from overflowing if the pump burns out or turns off.
3. Using a canister filter
Canister filters are familiar to those who keep fish. They can also be used to create waterfalls and streams inside large terraria, and are especially useful for enclosures that incorporate a big water area or house semi-aquatic amphibians which may do best if their water is filtered. Canister filters are also convenient to use because the sit outside of the terrarium for easy access. They also mechanically remove particles from the water, allow for chemical filtration (using activated carbon or other filter media like this is not always necessary however), and provide additional surfaces on which beneficial bacteria can grow. Before using a canister filter to create a water feature, it’s important to consider the size. Even the smallest models have a minimum flow rate of near 100 GPH, so canister filters should generally only be used on tall terraria, or for setups where a fast moving stream is required.
Last updated 05.03.09