Lighting for Your Pet Chinese Water Dragon

Heat and UVB Lighting Choices

Chinese Water Dragon in captivity

Mark Carwardine / Photolibrary / Getty Images

Pet water dragons require special reptile bulbs to light and heat their enclosures. Without appropriate lighting, water dragons can develop a multitude of problems. By knowing what kind of lighting your water dragon needs you can prevent these problems and help your pet live a long and healthy life.

Heat Lights for Water Dragons

The bulbs needed to heat an enclosure all fit in the same type of fixture, an incandescent ceramic socket, and can be purchased from almost any pet store. Heat lights, and not undertank heaters or hot rocks, are recommended as the primary source of heat for your pet. Submersible water heaters should be used to help heat the water dragon water.

Water dragons should have a basking temperature in the upper 80s and a cooler side of their tank in the upper 70s. The water should remain in the 80s.

Ceramic Heat Bulbs

Ceramic heat bulbs provide no light to an enclosure but they do provide heat. Just like regular incandescent light bulbs, they come in different wattages. The wattage needed depends on the size of the enclosure and if any other heat bulbs are used. Unlike regular incandescent bulbs, they last for an extremely long time, making them more cost-effective, but they do not deliver UVA rays. Therefore, these are a heat assist device to a bulb that emits UVA rays (full spectrum fluorescent or UVA ray emitting heat bulb). Make sure these bulbs are not placed on a surface that will melt.

Mercury Vapor Bulbs

Mercury vapor bulbs are for very large enclosures. They are very powerful UVB emitters but also give off heat. Unless you have a huge enclosure for your dragon and can hang the mercury vapor light several feet away from your pet, these are not typically good options for water dragons.

Incandescent Heat Bulbs

These are your typical heat lights that emit light, UVA rays, and varying wattages of heat. Different bulb sizes and shapes are available, as well as colors of light (wavelengths). Daylight bulbs are regular white lights, nightlight bulbs are blue/purple lights (make sure the bulb isn't painted glass but is, in fact, blue/purple glass), and nocturnal lights are red (don't use painted bulbs). The wattage needed depends on the size of the enclosure and if any other heat bulbs are used.

Basking lights are shaped to direct heat into the area directly below the bulb as opposed to the entire tank and are usually shaded on the sides to assist in directing the light downward.

Halogen Heat Bulbs

These bulbs do all the same things as incandescent heat bulbs and even though they cost a bit more, they emit more heat, light, and UVA rays than an incandescent bulb of the same size. They also usually last longer and use less energy than incandescents.

Some halogen bulbs fit in incandescent fixtures and others fit in halogen fixtures. Make sure your bulbs fit into your fixtures before purchasing them.

UVB Lights

Water dragons and most other reptiles require UVB light. This is an invisible wavelength that the sun naturally emits to help reptiles metabolize calcium that you feed them. Without it, your water dragon may be lethargic, not eat, and develop metabolic bone disease, among other things. Water dragons need 10 to 12 hours of UVB light daily to stay healthy.

Aside from sunlight (not filtered through a window), there are a couple of different sources that give off invisible UVB rays. Fluorescent bulbs and mercury vapor bulbs are the two most commonly used sources of UVB in the pet world.

Fluorescent Bulbs

Special fluorescent bulbs that fit into fluorescent fixtures give off varying levels of UVA and UVB (usually given as percentages) rays. These full-spectrum bulbs run out of rays before the lights burn out, therefore they need to be replaced per manufacturer recommendations, or every six months.

UVB bulbs are to be placed six to eight inches from where your water dragon can get to soak in the invisible rays. Also make sure the bulb is not placed on a plastic, plexiglass, or glass surface. These types of substances will block the rays from penetrating where your reptile needs them. Newer research also shows that the typical metal mesh screen commonly used for reptile tanks blocks a significant amount of UVB rays as well. Therefore, try to mount your bulb on the inside of the enclosure to make sure as many rays reach your dragon as possible.

Mercury Vapor Bulbs

Mercury vapor bulbs serve more than one purpose for your water dragon but are only for very large enclosures. They emit both UVA and UVB rays and they also provide heat for your enclosure. This allows you to use only one bulb to provide both heat and the important UVA/UVB rays in place of the usual two.

These bulbs last a great deal longer than fluorescent bulbs and heat bulbs and there is some discussion in the reptile community that mercury vapor bulbs can be dangerous to reptiles because of the intensity of the UV rays produced by these bulbs. Despite the worries, several reptile owners have never had a problem. If you do decide to go with a mercury vapor bulb, be sure to provide plenty of shade opportunities in the enclosure, use a ceramic socket for the bulb, and keep a minimum distance of 12 to 24 inches between your reptile and the bulb for safety reasons.

Compact Fluorescent Bulbs

These bulbs do all the same things as the regular fluorescent bulbs but they fit in an incandescent fixture. They also use less energy than a fluorescent bulb and should last longer but some research shows the UV is much too high for reptiles and they don't last as long as they should. They are also only good for small enclosures since they concentrate their light in one small area instead of several feet like a traditional fluorescent tube light does.

By offering appropriate heat and UVB lighting to your pet water dragon you can avoid a plethora of problems (and several visits to your exotics vet).