Probably the most frequently asked topic by new bearded dragon keepers is how to properly set the temperature in the vivarium.
It’s a pretty tricky thing to get right from the start, which is why it’s always recommended that you set up the vivarium and have it running for a week or so before getting your bearded dragon. Slight adjustments while you fix it can make the temperature go up or down, which would not be very comfortable if you are busy while playing.
The first thing to consider is where you install the nursery. You don’t want it in direct sunlight, or in a place where there are a lot of drafts, as this will cause your temperature to fluctuate. Placing it in a sheltered, shaded part of the room is a good start.
Bearded dragons need to be able to thermoregulate: they will bask in the sun until they get too hot, then retreat to a cooler spot to cool off. So you should have a basking spot with a temperature of around 41°C (105°F), and at the other end of the vivarium it should be cooler, with a temperature of no more than 30°C ( 85°F). Lower than this is fine.
To do this you will need to have a lamp that emits heat on the ‘hot end’. Bearded men are drawn to sunbathing under bright lights, so a nice bright 60- or 100-watt bulb is ideal. You don’t need to buy the expensive ones at reptile stores – a regular household one of the correct wattage will do just fine. Ceramic lights that do not emit light are acceptable, but the bearded dragon may not be as attracted to basking under them. That said, one of our bearded men has always had a ceramic bulb and sunbathes very well. Ceramic lights also have the advantage that you can turn down the heat at night without a light disturbing your sleep. However, most houses are warm enough that bearded dragons don’t need additional heat at night, as long as your house doesn’t go below 60f (16c) for an adult, or 65f (18c) for a juvenile. Bearded dragons need a good drop in temperature at night in order to sleep well.
The temperature should be controlled by a thermostat that turns the heat lamp on or off to maintain a constant heat. The type of lamp you choose will determine which thermostat you should buy. A dimming thermostat gradually reduces and increases the power of the lamp, a pulsing thermostat turns it on and off. If you have a heat light, then a dimming thermostat is necessary; otherwise it will continue to burn out the bulbs. A pulsating thermostat can be a little cheaper and can be used with ceramic light bulbs.
The most important thing to remember is that the thermostat should be used to keep the cold end cold. The sunbathing spot is the actual place where the bearded man will lay down to sunbathe. This can be adjusted later, and by adding branch rocks you can raise or lower the basking spot until it is at the right temperature. It’s not all the ‘hot end’ of the nursery that is trying to get to that height.
Place the thermostat probe near the cold end of the viv, turn on the heat and leave it for a few hours. A good digital thermometer with dual inputs and a dual readout is great for being able to see temperatures at the hot spot and extreme cold at the same time. Your goal is for the cold end to be below 85f (30c) and the basking spot to be 105f (41c). If the extreme cold is correct, measure the temperature in the basking spot and add your rocks or branches or remove them to try to get to 105f (41c). If the cold end is below 85°F (30°C) and you cannot increase the temperature of the basking spot, move the probe slightly toward the center of the vivarium. Once again, let sit for a few hours before rechecking measurements. You should continue this until you have the correct temperatures on the cold end. It doesn’t matter if the cold end is below 85f (30c).
Once you have the right temperatures, go outside and stop playing. Wait a couple of days and then check again. Make sure you have the UVB tube on at the same time as it will give off some heat.
If you find your vivarium is too hot and you can’t turn the temperature down low enough on the cold end, check to see if there are enough air vents at the back. There should be at least one at each end, one towards the top and one towards the bottom. You can add additional vents if needed.
If the temperature is too high in the middle of summer you should consider investing in a fan for reptiles. A separate thermostat can control this, and can be programmed to activate when the temperature rises above a certain level.
Once the probe is in the right place, your temperatures have stabilized, you should not need to adjust the settings. Now you can introduce your bearded dragon to its new home.