Reptile husbandry is largely an exercise in climate control. Proper humidity and temperature are crucial; stress, illness and anorexia are risks otherwise. Generally, reptile keepers maintain proper humidity and temperature through observation and manual adjustment, though some devices on the market automate the process.
You can provide supplemental heating from above by using a heat lamp, ceramic heating element or radiant heat panel. To care for species that prefer ventral heat, use heating pads or heat tape. Heat panels, tape and pads must be used with a regulating device like a rheostat or thermostat. Experiment with the heat lamp's bulb wattage to adjust the temperatures in the cage. Coordinate the on-off cycle of the heat lamps and other light-emitting devices to mimic the animal’s natural habitat; supplemental nighttime heating with red or blue lighting. Adjusting the cage insulation and airflow can help you to further fine-tune the cage temperatures. It is important to provide most species with a thermal gradient -- one side of the cage should provide a high-temperature basking spot, and the temperature should be cooler at the other side of the cage.
Add more water to the habitat or reduce the airflow to raise the humidity; but, as reduced airflow can cause stagnant air, it is generally preferable to increase the amount of water you add. The first step is to increase the size of the water bowl -- surface area is more important than volume, so use the widest water dish possible. Use water-retaining substrates like cypress mulch or organic potting soil that slowly release water into the air. Keep the substrate damp but not wet; avoid perpetually wet conditions and allow the cage to dry out periodically. Finally, you can mist the cage with lukewarm dechlorinated tap water to increase the humidity. Keeping a cage dry enough is rarely a problem, but if necessary, reduce the size of the water bowl, use a substrate like sand or wood shavings that doesn’t retain much moisture, and increase the airflow in the cage.
Manual Control and Monitoring
Most keepers engage in manual control of their climate; they check cage temperatures and humidity levels frequently, and make adjustments as necessary. To an extent, this is a good practice; constant observation is necessary for catching illness or other problems before they become serious. Conversely, you won’t be able to keep the temperatures as consistent as automated systems will, and some keepers are caught off-guard by the drastic temperature fluctuations that occur during relatively minor seasonal changes.
Automatic Control and Monitoring
Some automatic climate controls are popular; thermostats, once used only by professionals, are now widely used by novices. Thermostats monitor the temperature of your heating devices constantly, and adjust as necessary to maintain a consistent temperature. You can find a thermostat at virtually any pet store and should use one with any reptile cage. High-end units will produce much more consistent temperatures, have more features and can simultaneously control more than one cage. That said, even an entry-level model will give you and your herp much better chances for success. Misting systems are available; if you use one in conjunction with a timer you can schedule rain showers. Additionally, you can use an automated unit that will measure and maintain the humidity of a cage when attached to a misting device, much like a thermostat does for the temperature.
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