How Often To Change Each Bulb In Your Bearded Dragon’s Tank

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bulb change frequency title card

So, you’ve taken the time and care to install the best possible basking and UVB lights in your bearded dragon’s home. All your temps are spot on, and your beardie is living their best life!

Now what?

As we all know, light bulbs eventually burn out. And we don’t want to leave our little scaly friends in the dark, right?

So, when should we change those bulbs? Should we wait until they go out? Should we change them more often than that?

There are a total of seven different kinds of bulbs you might find in a bearded dragon’s tank. Each is slightly different than the other, so let’s take a look at each and when you should change it.

How Often To Change Each Bulb In Your Bearded Dragon’s Tank

You should change all of the bulbs in your bearded dragon’s tank every six months. This is a short enough time that bulb effectiveness won’t dip to dangerous levels and will all but eliminate the possibility of them burning out. Keeping this schedule is critical to your bearded dragon’s health.

Yes, there are some variations, but this is the quick and simple way to stay on top of your lighting. Need more detail? Read on!

Why ALL Bulbs Should Be Changed BEFORE They Burn Out

A very small reason we place bulbs in our bearded dragon’s tanks is to provide them with light. If that’s all that mattered, we could simply wait for each bulb to burn out before changing it.

That would be far simpler and less expensive than doing things correctly. Unfortunately, what you might save in light bulb expenses, you would more than make up for in vet bills!

The primary function of a basking lamp and bulb is to heat the basking spot to a specific temperature range. That temperature range is what allows your bearded dragon to digest their food.

From the moment you install a new basking bulb, the amount of heat it can produce diminishes slowly over time.

bearded dragon under a basking bulb that needs change
Bacardi enjoying her basking bulb.

When your basking temps drop below a certain level, your bearded dragon can no longer digest their food! See how vet bills might come into play if your lighting is off?

At some point, your bulb will still be giving off plenty of light while at the same time not being able to give off the required amount of heat. You need to change your bulb before this happens.

Your UVB bulb has a similar issue. Its primary purpose is to provide a healthy level of UVB light. This, among other things, allows your bearded dragon to synthesize Vitamin D and properly use calcium.

The UVB comes from the phosphors inside the light. Over time, those phosphors diminish and give off less UVB. 

A UVB bulb can actually get to a point where it gives off virtually no UVB rays but still emits light just fine!

So, as you can see, your bulbs stop providing your bearded dragon with health benefits long before they stop giving light. And that’s why we need to adhere to a relatively strict schedule of bulb changes!

How to Know When Each Bulb Needs To Be Replaced

A very common question we get is whether or not there is a way to measure precisely when a bulb needs to be replaced.

While the technically correct answer to that question is yes, we don’t know many people who would want to go to the expense or trouble to do this.

You can measure your basking spot temps daily with a temp gun like this. This should be done daily anyway, and a temp gun is an inexpensive necessity for bearded dragon owners.

UV meter
UV Meter

Then, when moving your basking light can no longer achieve the temperature range you need, you change your basking bulb.

Similarly, you could purchase a UVB meter like this one, measure your UV levels across the enclosure daily, and then replace the bulb when UV levels fall below an acceptable level.

Those might be viable options if you are a breeder, herpetologist, or zookeeper. For the rest of us, they are not.

Checking bulb output daily in an effort to get a few more weeks or months out of each bulb isn’t cost or time-effective.

It is much easier to put yourself on a fixed bulb-changing schedule that ensures each bulb is changed well before its effectiveness dies out.

If you know that bulb A reliably lasts eight months before a significant drop off in healthy attributes, then changing it every six months ensures you never run into a problem.

Are you removing a bulb that still has some life left? Yep. Hang on to it as a backup in case your current bulb burns out prematurely.

But don’t try to squeeze every last moment of life out of it! It’s your bearded dragon who will pay the price!

Replacement Schedule By Bulb Type

As a general rule, we change both our basking lamp and our UVB bulb every six months. We do this on the winter and summer solstices as that’s a natural reminder of changes in light.

But some bulb types can last longer and don’t need to be changed every six months. Here is a chart showing each bulb’s decay rate and expected lifespan.

Again, we recommend making this as simple as possible and getting on a six-month schedule, but for those of you who are engineers and much more analytical than we are, here ya go!

Bulb TypePurposeReplacement CostApprox. Total LifespanRecommended Replacement
IncandescentHeatna1,000 hours6 months
Basking*Heat$7-$101,000 hours3-6 months
CFLHeat + UVB$10-$1510,000+ hours6 months
MVBHeat + UVB$35-$5024,000 hours18 months
Fluorescent Light Tube*UVB$45-$7020,000 hours6 months
CHE*Heat$4-$610,000 hours12 months
HalogenHeat$5-$152,000 hours3-6 months
*These are the only two bulb types we recommend

To learn more about the three types of bulbs we recommend, check out these guides:

The Verdict

Lighting, UV, and temperature are critical things to get right in your bearded dragon’s home. Without them, bearded dragons can get sick and even die. (source)

Don’t leave those things to chance by pushing the lifespan of your bulbs. Instead, get on a regular replacement schedule and ensure your bearded dragon’s health throughout its lifetime!

Further Reading and Sources

Bearded Dragon Husbandry

Vitamin D3 and UV Exposure

Vitamin D and Skeletal Development of Young Bearded Dragons with Different UV Exposure Levels.

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Tim Steward is a life long pet owner who is currently raising a beautiful little beardie named Bacardi along with two Australian cattle dogs named Anny & Beans. Bacardi is one in a long line of bearded dragons that Tim has rescued, rehabilitated, and rehomed. Through Beardie Bungalow, Tim has helped thousands of beardie parents give the best possible life to their pets.

4 thoughts on “How Often To Change Each Bulb In Your Bearded Dragon’s Tank”

    • If a light bulb is too expensive twice a year, then so is a bearded dragon. UV light is critical to their health and letting your bulb go until it burns out is dangerous and very unhealthy. Metabolic bone disease comes on over a long period of time, but is not reversible. It’s a life threatening disease that at a minimum will cost you a ton in vet bills and make your beardie miserable for the remainder of its life.

      I’ll be blunt. If you don’t change the light bulbs, you should not have a bearded dragon.

  1. We let our first UV light go until it burned out, which was about 2 and a half years. When we put the new one in, our beardie got more active, started eating more, and his colors started to pop more than we ever remember. You are 100% right that just because the light is still working doesn’t mean it’s giving the right amount of UV. We are really lucky little Albert didn’t get sick. We wouldn’t have had a clue as to why.


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