When we wrote our article detailing the cost of owning a bearded dragon, even we were surprised at how quickly things added up!
Because of that, it’s not unheard of for beardie owners to try to save a few bucks here and there. Sometimes, you can do that without a negative impact; sometimes, you can’t.
UV meters fall into this category.
They are expensive (you can see the price of the one we use here on Amazon). But they measure one of the most critical aspects of your bearded dragon’s environment: UV levels.
Do Bearded Dragon Owners Need A UV Meter?
Most bearded dragon owners do not need a UV meter. If using a standard height (18-24″) enclosure with an appropriately sized, reptile-specific high-output UV light, there is little chance of the UV levels being off. Tank setups outside these guidelines need a UV meter to ensure healthy UV levels.
In other words, if you are using a setup like we recommend here on Beardie Bungalow, you can rest in the knowledge that your UV levels are at a healthy range for your bearded dragon.
In short, that setup is a 36-48″ wide by 18-24″ high enclosure with a UV ballast that spans the entire tank width. Put a high-output (T5) reptile UV bulb in that fixture, and you’re good to go.
A UV meter is necessary if you want to create a setup that runs outside those guidelines. It’s the only way to ensure adequate and healthy UV levels across the entire tank.
Why UV Levels Are Important For Bearded Dragons
In the wild, beardies live under a cloudless sunny sky on most days. They get 10-12 hours of direct sunlight, with no bulbs or fixtures needed!
As in humans, sunlight helps them convert vitamin D to bioavailable calcium. Calcium is essential for bone health and a host of other metabolic functions. (source)
More specifically, calcium generated internally from vitamin D is critical.
Sure, we supplement regularly with calcium, but that is inadequate by itself. Orally administered calcium has remarkably lower bioavailability than that which is naturally produced by healthy levels of UVB rays. (source)
Calcium and vitamin D deficiencies are behind a host of bearded dragon illnesses, so it’s best to avoid that at all costs!
In other words, your beardie will get sick without the right amount of daily UV light exposure.
How Much of The Tank Needs UV Light?
All of it.
We’ve seen multiple folks online suggesting you only need UV on one side of the enclosure. That is not true.
Your beardie’s home should have two hides (places they can go when stressed or brumating)—one on the hot side and one on the cool side.
Those hides give your bearded dragon a way to get shade if they desire. But if they are outside those hides, they should be able to receive a healthy level of UVB rays.
Ideal UV coverage in a bearded dragon’s vivarium should be viewed as a gradient that covers the entire tank.
What Are The Desitred UVI Measurements in a Bearded Dragon’s Tank?
A healthy UVI (ultraviolet index) reading in a bearded dragon’s tank should range from 4.0-6.0 as measured by a UV meter. Aim for 6.0 in areas nearest the bulb and 4.0 in lower sections of the tank away from the bulb. Readings shouldn’t exceed 7.0 or fall below 4.0 in any part of the tank.
To read more about UV meters and whether or not you need one, see our article here.
Typically, you will want to check these readings weekly. If you see them dropping, it’s probably time for a new bulb. Occasionally, ballast issues can cause the same type of drop in UV output, but that is rare.
In that vein, ensure you also use the correct type of ballast and bulb (see our guide here). Not all fluorescent lights are the same when it comes to UVB output.
We did not buy a UV meter when we got our first bearded dragon. Our vet made house calls at the time, so he measured it for us on his first visit.
When we asked him if we needed one, he quickly said no. As long as we kept our setup and changed the bulbs regularly, we would always be fine (that’s the same tank setup we recommend here on Beardie Bungalow).
It wasn’t until we tried some creative new tank ideas and started helping others through this site that we purchased one.
So that’s our advice to you. You probably don’t need one unless you are doing something more than a single bearded dragon in a traditional tank setup.