Although there is a bit of disagreement over this, it’s safer to err on the side of caution and give your skink access to UV light. Here’s what you need.

There is a lot of misinformation, ignorance and outright conflicting information out there on the web regarding UV lights and blue-tongued skinks.

I’ll do my best to make it a bit easier for you.

My quick and short recommendation is:

In this article I will explain:

  • Why it’s a good idea to give blue-tongued skinks UV light
  • The best overall UV light
  • A completely cost-free alternative
  • Light bulbs you should avoid

Let’s get started.

Why Skinks Need UV Light 

There is a common belief floating around that blue-tongued skinks don’t need UV bulbs.

Apparently, one theory is that this belief stems from the fact that a lot of breeders do without them, and yet these skinks seem to be just fine.

Personally, I don’t find this theory all that convincing.

Typically blueys do not stay with their breeder for a long time, and it is hard to gauge the long-term effects of a lack of UV light simply because they “seem to look fine with the breeder”.

Another common reason that some people believe in this myth is the mistaken belief that your blue-tongue skink can get its UV light naturally.

This is also, just flat-out wrong.

There are 2 types of UV light that are beneficial for your bluey:

  • UV-A light. This is visible to our eyes, and helps to regulate things like a good sex drive, behavior and a healthy mood.
  • UV-B light. Crucial. This helps with the vitamin D3, which is critical to metabolize calcium properly. Without UV-B light, a blue-tongue skink is more likely to contract a calcium deficiency, which can lead a lot of things going wrong, such as developing metabolic bone-disease (MBD).

A blue-tongued skink placed in a terrarium that is indoors simply cannot get adequate UV light, even if it was placed next to a window.

This is due to the fact that windows block about 95% of all UV light.

You could always open the window, right?

Except that that is going to completely mess up your temperature gradient, at least when it’s cooler outside.

The bottom line:

It’s just easier to get a UV bulb and play it safe. 

The Best UV Light Bulb for Blue-Tongues

I believe that Mega Ray Mercury Bulbs are the best overall bulb for blue-tongued skinks.


  • 6-month warranty
  • Lots of different sizes
  • Emit both UV-A and UV-B light
  • Very effective, very good quality


They are expensive

These are my favorite becuase:

  • It contains both UV-A and UV-B light (you wouldn’t believe how many so-called UV bulbs don’t actually have UV-B light)
  • It comes with a 6-month warranty (super important!)
  • It comes in a ton of different wattages

The different wattages are:

  • 70 watts
  • 100 watts
  • 160 watts
  • 275 watts (you don’t need this)

The wattage actually isn’t important here, what’s important is the temperature in the terrarium. Basically, the more watts, the further away you can get from your terrarium while still keeping it hot. Other than that there really is no advantage to getting more watts.

The only real downside to these are the price. They are a bit expensive.

However, I have had nothing but good experiences dealing with their customer service staff.

This is just my personal opinion, but I would rather spend a bit more on a good bulb, and deal with a reputable company than buy a cheaper bulb that may burn out in a few months and need to buy another.

So, if you are on the fence, I would suggest reading some of the comments on their Amazon page, and decide for yourself.


  • Much cheaper than the Mega Ray bulbs
  • Emit both UV-A and UV-B light
  • Look nice as they are fluorescent bulbs


  • More likely to break
  • Warranty not as strong as the Mega Ray bulbs

A cheaper alternative to the Mega Ray Mercury Vapor bulbs are the Exo-Terra Repti-Glo series.

These are not bulbs however, but flourescent tubes. Obviously you would need an appropriate tube-fixture to pair it with.

They also work quite well and come in a few different sizes:

  • Repti-Glo 2.0. This is the smallest light and really doesn’t emit enough UV-B light to be viable for your skink. Ignore this model.
  • Repti-Glo 5.0. Emits a 5% UV-B light, good for Indonesian and non-A
  • Repti-Glo 10. Emits 10% UV-B light and is better suited for the Australian species.

The only downside to these bulbs is that they are a little bit more susceptible to breaking.

These two bulb series I would really have no qualms recommending. I think you are pretty likely to be satisfied with either.

A Cost-Free Alternative

There is a completely cost-free alternative to not only both of the above bulbs, but any UV light in general.

That is to simply take your animal outside. 

After all, the above bulbs are mere imitators of the sun’s natural, UV-producing sun-rays.

Purportedly, 1 hour of basking in the sunshine is equivalent to hours and hours of basking in a terrarium under a UV producing light.

I can’t speak as to whether or not that is true, but it’s most definitely true that the real thing is (obviously) going to be superior to everything else.

Of course, the downsides to this method are quite constraining:

  • You can’t take them outside during inclement weather
  • You can’t take them outside in cold weather
  • You will have to really keep an eye on them so they do not run away, get lost or are suddenly captured by a nearby predator

So, unless you actually live in Australia or Indonesia this is simply not really a practical solution if you are in a colder region.

Light Bulbs You Should Avoid 

You might be tempted to just get anything that has “full-spectrum UV” or some other type of clever advertising, but you really have to be cautious here.

Here is a quick list of bulbs that you should avoid.

  • Any bulb that does not emit both UV-A and UV-B light. This should be fairly obvious, but if it only produces UV-A light, it’s useless. And if it doesn’t produce UV-A light, your skink isn’t getting the full benefit of ultra-violet rays.
  • Incandescent bulbs.These are simple house lights that you find everywhere. The reason is quite simple, they don’t contain any UV. Avoid. These are usually marketed as “reptile lights” and simply are colored. They don’t produce any UV light. Useless.
  • Flood lights.These will do nothing but mess up your terrarium’s temperature gradient. They also do not produce UV.

The bottom line:

  • Blue-tongue skinks need UV light
  • The best, least-stressful way to ensure this is through a UV-emitting bulb
  • The 2 best are the Mega Ray and Repti-Glo series
  • Buy the Mega Ray if you can easily afford it, otherwise just grab the Repti-Glo