How To Choose A Thermostat
First thing first – how is your vivarium set up, and what animal do you have? Are the light and warmth provided by just one lamp or bulb, or is everything separate?
For example, if everything gets too hot, the bulb may need to be switched off temporarily. But if this bulb also gives them their UVA daylight, then plunging them into darkness in mid-afternoon will play havoc with their circadian rhythm. You will, therefore, need one of the dimming thermostats, or you will have to keep everything separate.
You will also need to ensure that your chosen thermostat will work with your lamp, as some are specially designed to work with just heat mats for instance, and will be overloaded if connected to the voltage of a bulb. This could break the glass, which is dangerous.
If your tank needs a certain humidity, you may also need a hygrometer, and there are some which combine everything all in one item. This does, however, mean there is more to go wrong as opposed to keeping it separate.
Types Of Reptile Thermostat
Perhaps the cheapest type. They work by checking the temperature and then turning the heat source on and off at intervals to adjust the temperature accordingly between the minimum and maximum settings. They would not be suitable for bulbs which also give off light, as it would plunge the tank into darkness frequently, but can be good for bulbs such as ceramic ones which give off no light, or cheap backup lighting.
These thermostats only work with non-visible sources of heat such as heat cables, mats and ceramic emitters. They send pulses of energy with more or less intensity depending on whether the temperature needs a boost, or dropping. This will help to keep the tank within the heat parameters you set, no matter how large or small these are.
This is the smartest option. Instead of turning the bulbs completely on and off, they are dimmed or brightened. It increases and decreases the power to the bulb as opposed to turning them off and on. This is best for bulbs which also give off light, as they won’t be plunged into darkness even though the light will be minimised temporarily. It will also prevent your pet from getting quite as much of a shock with the light pinging on and off.
These are best for heat mats which fit under a tank. Some reptiles can’t have this style of heater if they would have a risk of burns through basking, or it would be too much of intense heat, but if yours does it could be worth being able to monitor it through a thermostat. They will often be able to cope with the lower wattage, and will gradually increase and decrease the heat as opposed to switching it on and off.
Wattage/Power
Every thermostat will have a maximum power wattage that they can connect to, so you really need to ensure that your bulb or heater is compatible. If it is too powerful for the thermostat, it could mean your setup is compromised and one or the other will either stop working or become overpowered.
For instance, a thermostat with a maximum 600W power input won’t be able to control a bulb of 1000W. Likewise, if you buy a thermostat which can cope with 1500W and three input devices, there may be a limit on how much each input can cope with – it could monitor three heaters of maximum 600W each, but not one item of 1200W for instance.
Temperature
Every thermostat will have a minimum and maximum temperature monitoring level. A common option is something around 18 and 35 degrees C, so if you have something which needs to be even cooler at night or one for a desert animal/basking lamp, you may have a bit less choice.
Timer
This will allow you to change the temperature throughout the day, and especially when switching from day to night. Most setups will likely benefit from a thermostat with a timer, but it may not be needed if controlling anything other than a lightbulb, or if you have separate night and day equipment anyway.