Three Aspects to Reptile Lighting
One of the most important things a reptile needs is correct lighting. It not only regulates their photo period and provides essential UVB rays, it also allows them to see there environment. Now this last one sounds pretty obvious but what most people don't realize is that most reptiles can see into the UV range and some into the IR range. So providing a UV light is important for them to feel more at home and can stimulate better appetite and activity. Some of their food sources would faintly glow in UV light and that will make it more appealing to your reptile. There can also be too much UV though. so I recommend not using a light higher than 8% UV. One major concern is the use of compact coil lights. They produce too high a concentration of UV light and can cause blindness if the reptile can get too close to the light.
Regulating the photo period of a reptile isn't always necessary. You just want to make sure your pet gets enough light. twelve hours of daylight is usually ideal. If you are planning to breed your pet reptile sometimes changing the amount of daylight verses night can trigger them to want to breed. Some reptiles are nocturnal and can benefit from a night light. They look kind of like a black light and help your reptile see at night.
Most reptiles need vitamin D3 to absorb and process calcium. A light that has UVB will help them produce vitamin D3 in there metabolism. You can also use a vitamin D3 supplement to help them out with this. Some reptiles will also benefit from a calcium supplement. Depending on what kind of pet you have will determine if you need to give them any supplements at all. Most snakes don't need any. Other carnivores get what they need from their prey. If your reptile is an herbivore or insectivore they probably will need a calcium/phosphorous supplement of 2/1 ratio. Phosphorous free calcium is for carnivores as the get most of their phosphorous from there prey.