For many hobbyists, the rationale behind a drip watering system is simply to provide "fresh" drinking water to animals that cannot (or will not) respond to traditional water bowls. The drip watering system is also a way to increase cage humidity, an important factor in the permeable-skinned amphibians and anoline lizards. A drip watering system (or its next-generation representative, the rain chamber) not only rehydrates an animal, but also stimulates natural activity patterns. Both the ambient temperature and the water temperature are controlled, creating a soothing, revitalizing environment.
Which Animals Need a Drip System or Rain Chamber?
The answer is, almost any type of reptile or amphibian, except desert forms. Rehydration is especially important for new imports. Many imported species are too stressed-out to drink water from a dish, even when (or if) it has been offered. These animals may have been kept in crowded holding facilities for several weeks before shipment to a stateside wholesaler. Animals most likely to need rehydration are the tropical species, those that generally originate in areas of high humidity, and those from seasonally wet/dry areas.
Two or three sessions with a drip system may be all it takes to rehydrate an animal. The sessions should be a few hours in length, and can be repeated after a wait of three to twelve hours. After a few sessions, your animal can then go into a conventional caging/watering system.
There are animals that will need a drip watering system on a daily or every-other-day basis. Tree vipers of several species (including Tropidolaemus sp.), tree boas (Corallus sp.), leaf-tailed geckos (Uroplatus sp.) and chameleons (Chameleo sp.) do not normally drink from quiet, standing water. Ground-level pools of water are as foreign to them as treetop living would be to a dog. "Lapping up" water is not an option for amphibians such as treefrogs and salamanders; they absorb their water through their skin.
Obviously, it is important that the environmental water provided to these reptiles and amphibians is clean. Setting up a hydration system for occasional or everyday use can be simple and relatively inexpensive. You can choose between a closed system, one where the water recirculates, and an open system, which uses a continuous flow of water from your tap.
Whichever route you go, there are a few parameters you'll need to provide. The first is the system itself. The second is a way to drain off the water that isn't absorbed/drunk by the animals. Third, you'll need to use dechlorinated water, unless you use well water. For closed systems, where the water recirculates, add a dechlorinator solution to the water before you start the system up. Closed systems are fine except when the animal is one of the tree vipers and is likely to defecate as a result of the "rain." To put it mildly, a closed system would do that animal no good at all. For open systems, which use a continuous flow of water from your tap, you'll need an activated charcoal aquarium filter. Lastly, you'll also need to control the temperature of the water being used to a range of 73-78 degrees.
Types of Chambers
There are basically four types of drip systems/rain chambers. The simplest is based on a plastic bucket with a pinhole opening in the bottom, called a drip bucket. A more complex type of drip system/rain chamber uses a wire mesh cage placed inside a utility sink. Another uses a large covered plastic trashcan, while the most complex uses a drilled length of PVC pipe and a rheostat and timer. Once you understand how these types of rain chambers work, you'll be able to modify one of the types for your own needs.
For the drip bucket, you just punch one or two pinholes in a plastic bucket, fill the bucket with room temperature dechlorinated water, and place the bucket atop the animals' cage. Position the bucket so the dripping water drips onto plants or driftwood in the cage. The more obvious the motion of the water, the more likely the animal(s) are to find it and drink from it. You can place a dish inside the cage to catch the droplets.
If you have access to a cage of wire mesh over a wooden frame, and if the weather is good enough to place the caging outside, the water from a drip bucket can be allowed to drip through the cage to the ground below.
Another simple hydration system uses a wire mesh cage atop a utility sink and a recirculating filter inside the sink. The filter's output nozzle has ¾-inch wide aquarium tubing attached, which leads to a sprinkler head atop the cage. Add enough room temperature water to the sink to cover the pump, and add a dechlorinator to the water. Turn the filter on, and a gentle stream of "rain" should flow through the pump, into the tubing, through the sprinkler head, through the cage, and back down into the sink, where it will be filtered and sent upward again. If you plug the filter into a timer, you can provide a rainy period for whatever time you select. You can make an open system from the sink and wire cage arrangement if you run the aquarium tubing from the spigot of the utility tub to a sprinkler head placed on top of the cage. The water flows down through the tub's drain. This direct method is less suited for frog and salamanders, due to the presence of chlorine compounds in your drinking water. For both of these systems, you must use wide aquarium tubing rather than a section of garden hose.
A large covered plastic trash can serve as a rain chamber. Punch a number of holes (you can't have too many) along the bottom edges. Add branches inside, near the bottom, to serve as perches for your animals. Wedge them into place, or glue them into place with silicone adhesive. Cut a good-sized hole in the lid, and use silicone adhesive to cover the opening with a cut-to-fit piece of 1/8 inch or 1/4 inch hardware cloth. The screening will enable you to peer inside the trashcan and see your animals are doing without opening the container.
Put the trashcan in your shower stall. Turn on the shower and adjust the spray to slow or moderate and the size of the nozzle openings to "fine." Adjust the temperature to 74-78 degrees Fahrenheit (this will feel cool to your hands, so use a thermometer to check the temperature). Turn off the shower, and slide the trashcan to the edge of your shower stall so you can put the animals onto the perches inside the trashcan. Snap the windowed top into place. Turn the water back on and check and adjust the temperature if necessary. Slide the trashcan into place under the showerhead. Set a timer for an hour. This sort of a chamber is useful for animals that tend to defecate during a rainstorm, because the water isn't recycled, and it's easy to empty any debris into your toilet or outside.
The fourth type of rain chamber uses a recirculating pump to pull water from the bottom of an aquarium up into a length of PVC piping or a sprinkler head placed over the tank. The pipe has 1/8 inch holes drilled along its bottom side that allows the water to drain through. The animals are placed atop a false floor of hardware screen or plastic egg-crate that is held above the dechlorinated water with a couple of bricks. Obviously, the tank itself must be covered with a screen top that will permit the water to drip through while making certain the animals can't hop or crawl out. You can add an aquarium heater to the water in the bottom of the tank to control the water temperature.
These drip systems provide an efficient, easy, and effective way to rehydrate a reptile or amphibian. To help keep your animal in the best of health for the rest of its 5 to 20-year life span, check the ambient humidity, altitude and annual rainfall in its area of origin. You may need to make caging modifications to provide either more humid or a more arid environment.