Manila Bulletin Publishing Corp



So let’s say you’ve determined the level of UV a reptile needs based on their species and their zone in the chart. Now, it’s time to choose a bulb and find out how to use it. In general, you may find bulbs with UVIS of 5.0 or 10.0 and think that they’re too strong, but it’s important to remember that the farther away the animal is from the bulb, the less UV they will get. The key is to distance the bulb in such a way that when the rays hit the animal at a certain height (preferably around their basking spot), the level of exposure remains in their suggested zone. For example, for a bulb with a UVI reading of 5.0 to be placed 10 inches away from an animal, the actual UV the reptile receives will be at a UVI of around 0.4-0.7 only, which is suitable for crepuscular or shaded animals (those in Zone 1). Another example is using a UVI 10.0 bulb and placing it five inches away from the animal. This would put the UVI at around 2.6-3.5, which is the UV required by midday baskers (those in Zone 4).