Reptile & Amphibian Forums

Hi,
I am moving my bd to a 55 gallon tank in the next few weeks and I was wondering what size mercury vapor might be appropriate. The room temperature is 73. Thanks,
Zach

I don't think Mercury Vapor bulbs put out enough heat to be the UVB and heat source because of the distance they need to be away to be safe.

I also think a 55 gal. is a mistake for a Beardie. They are too narrow (12" and are only half of the recomended floor space. A 75 gal. is just as long but 18" deep which is better and 50% more floor space. Or a 40 breeder is only 3 feet long but still has more floor space than a 55.

With a 75 or 40B you could use a linear UVB tube and a basking bulb. A 55 is too narrow for this.

The accepted minimum for a Beardie is 4' x 2' or 8 sq. ft.

Bulb wattages are largely irrelevant, but probably better to use less than more. You could heat an entire 55G tank with a 15 watt incandescent if set-up correctly (moving basking surface closer to the light) but agreed with BDlvr 55's are too narrow for an 18-24 inch lizard. Better to go with a bigger cage.

Mercury Vapor FLOOD LAMP Bulbs are a controversial subject when discussed in the lighting category. I have used them before and have had no problem with them, especially LIKED the fact that they dont need to be replaced every 6 months-12 months like a Strip UVB Bulb would have to be. You can replace the Mercury bulbs every 2 years. But the reccommended Placement of the bulbs always boggled me because I dont think it matched up with the correct UVB absorbtion that is required by Beardies. I broke the rules and placed them a little bit closer (6'' or so) and never had a problem. Never encountered eye problems or anything....
www.AtlantaBeardedDragons.com

I expect 55 gal tanks come in different shapes so some may be wider than others...but even then, what you want for an adult dragon cage is one that is at least 4' long by 2' wide. Height can be anywhere between 18-24". Mercury vapour bulbs are better for bigger tanks than bearded dragons typically need....and often don't put out enough heat to serve as the primary basking lamp. They do need to be at least 18" above the basking spot which puts them outside most standard glass tanks. As they are outside, heat escapes far more so they don't serve very well as a basking spot

IN a 24" high cage, you could mount the MVB inside the cage...which will help prevent heat escape (providing the top isn't all screen which lets heat escape quickly. But with an inside mounted MVB bulb, you have to make sure the basking spot is very low...only a few inches above the 'floor' of the cage (and this includes the thickness of any substrate, as well as the basking spot, if sitting ontop of sand.(though better to have the basking spot flat on the floor of the cage, and have sand around it). As a MVB itself may hang 4-6" from the fixture (some are pretty long bulbs) you really dont' have much room for any height to a basking spot in a 24" cage. You have none for any cage that is less than 24".

So, you would need to get a higher cage than 24" for MVB to be mounted inside a dragon's cage...and to me, this just is a waste of money when a basic 8 or 10.0 florescent bulb (the long tubes, not the compacts) will still provide enough UVB light, last just as long as the MVB and you can have the basking spot alot closer without any harmful effects. You still need a warm basking lamp but in most situations you need one with a MVB anyway.

Thus, your best bet is to first, get a bigger cage than you plan...if you have any carpentry skills (and you don't need alot really to build a cage, just a little planning ahead) or know somebody who does and enjoy working with their hands, build your own cage. It doesn't cost much in material to build a 4'x2'x2' cage or even a 4'x2'x 18". You can go bigger as well, as these are the minimum sizes. All you really need is a saw, drill and screw driver (or you can use a hammer and nail but I find using nails tends to just split wood..plus it makes it impossible to take the tank apart of needed..also using a drill and screw driver eliminates hitting thumbs with hammers LOL)

You can use melamine to build your cage...pretty straight forward to make a big rectangle with front mounted doors. The doors can be screen, in a frame, sliding glass doors or plexiglass mounted in a wooden frame (glass can be used too but easier to drill holes through plexiglass...and glass may require using a router to make groves in the frame for it to sit on).

I don't have any special carpentry skills nor do I have any fancy power tools..other than a standard drill. There are also plenty of 'Do It Yourself' sites with plans on how to build cages, even if they may not be specifically for bearded dragons...all you have to keep in mind is it must hold heat well, have plenty of floor space and simple enough to match your building skills.
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PHLdyPayne

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