Unless your red-eared slider is in an outdoor pond, it will need artificial light. This is what you need to know about red-eared slider lighting requirements.
Red-eared Slider Lighting Requirements
For lighting, there are only really a few things that are essential:
- You’ll need to provide a UV-B light.
- The basking area needs to be completely dry.
- The temperature should be between 90 and 95 degrees fahrenheight.
If you are more of a visual learner, you can watch my video below where I dive into everything you need to know about lighting for a red-eared slider.
If you are looking to purchase a basking light, below is a video where I review a cheap basking light that I use for my red-eared slider.
As mentioned in my video, your light needs to produce UV-B light.
If you don’t have the proper light, it can cause your red-eared slider to not bask.
Best uvb bulb for red eared slider
The best UV-B bulb for a read eared slider is the Zoo Med Aquatic Turtle UVB kit. It come with a UVB bulb as well as a heat lamp. However, it is also important that your turtle gets UV-A light.
Best basking lamp for red eared slider
  | UVA UVB Turtle Basking Light | Price: ~$20 | Check Price On Amazon |
  | Turtle Lamp Combo Pack | Price: ~$20 | Check Price On Amazon |
  | UVA UVB Replacement Light Bulb | Price: ~$22 | Check Price On Amazon |
The best basking lamp for a red-eared slider is one that emits both UV-A and UV-B light. It needs UV-A to help regulate their metabolism and mood, and it needs UV-B for the production of Vitamin D3.
Without this vitamin, your turtle will eventually become weak, and eventually, die. Here is a link to the bulb I use. It has worked great for all my turtles, and you can click the picture below for more details. It is also Compact Fluorescent so you will save money on electricity.
According to a study conducted by the Journal of Veterinary Medicine in 2006 that measured levels of 25-hydroxyvitamin D3 in red-eared sliders, those that basked under a UV-B light had significantly higher amounts of the vitamin than those that did not after a 4-week period.
The UV-A is the easy part. They get that with natural lighting, and moreover, if you have a UV-B light, it will also emit UV-A. However, if you have a UV-A light, it might not necessarily emit UV-B.
Here is another recommendation for a cheap UV-A/UV-B Light: UVA UVB Basking Lamp with 360°Rotatable Clip.
Secondly, your turtle will need a basking area, which is a spot, somewhere in their aquarium or habitat, where they can get completely out of the water and lay in the light. Although red-eared sliders are aquatic, they cannot stay in the water all the time, or fungi, mold and more will grow and infect their shells.
Here is a link to the basking platform I use for my turtles.
Lastly, red-eared sliders really thrive with a basking temperature in the 80 to low 90-degree Fahrenheit range. Too hot and they won’t bask (and thus won’t receive healthy UV-B). Too cold and they will become susceptible to illness.
Can I Use A Regular Light Bulb For My Turtle?
Yes, you can absolutely use a regular, incandescent light bulb for your turtle.
For your heating, that is. Not to meet your overall red-eared slider lighting requirements.
If you live somewhere a bit colder, it may be very difficult to get your basking temperature in the 80 to low 90-degree Fahrenheit range with just one UV-B bulb. This is totally normal.
What a lot of people do is use a second light bulb for heating purposes.
If you can’t get the basking temperature to at least 80 degrees Fahrenheit (27 degrees Celsius), consider using a halogen, ceramic heat emitter or even a regular light bulb to get it hotter.
How Many Hours Of Light Does A Red-eared Slider Need?
You’ve got your UV-B producing light bulb. You’ve got the temperature in the basking spot right at a nice 84 degrees Fahrenheit.
But, now you need to know long to keep the light on?
A good rule of thumb is between 8 to 12 hours. You might think this is too long, but you have to first realize that UV-B light only approximates natural sunshine. It cannot mimic it perfectly.
How much sunshine approximates how much UV-B light from an indoor bulb? There aren’t any scientific studies that I’m aware of that give you an exact approximation, but basically, your turtle will get A LOT more UV-B underneath the sun than under a UV-B producing light bulb.
Compared to the sun, UV-B emitting light bulbs are quite weak. They just can’t compare to the sun. In fact, I’ve read estimates that anywhere from 10 minutes to an hour of sunshine is equal to 12 hours underneath a UV-B bulb.
Of course, this all depends on your location, the time of day, whether you are directly underneath the sun, etc. But essentially, nothing can compete with good ole, natural sunshine.
If your aquarium gets too much or too little light, it could be the reason why your aquarium plants aren’t growing.
Can I Put My Turtle In The Sun?
All things being equal, by far the best course of action to make sure your red-eared slider gets UV-B light, is to put it outside to soak up some sunshine.
So, to answer the question, yes! You can absolutely put your turtle in the sun.
However, there are a few reasons why you might not want to:
- Putting your turtle outside may subject it to potential predators. Basking turtles are easy prey for certain birds, cats, foxes, etc. Unless you have good protection from outside predators, it just may not be safe.
- During certain times of the year, this is just not feasible due to the low temperature. If you’re in Minnesota during the first week of January, it’s probably not a great idea to put your turtle outdoors! This can increase the risk of respiratory infections.
Do Red-eared Sliders Need Light At Night?
You absolutely don’t need to provide a UV-B light, or any type of light at all, over the night.
The entire point of a UV-B light is to mimic the sunshine. To provide indoor turtles with heat and UV-B light.
You definitely don’t need to keep your lights on throughout the night.
What you may need, however, is to provide a heat source. Especially for places where the temperature drops quite low at night. If the air temperature drops down into the low 50s where your aquarium is housed, I would consider adding another heat source.
A ceramic heat emitter can do this to maintain some heat on the basking area, and a turtle water heater can keep the water temperature warm. Of the two, the water heater is by far more important. In my experience, many red-eared sliders sleep in the water at night.
Do Red-eared Sliders Need A Heat Lamp?
All red-eared sliders kept in indoor enclosures need a heat lamp. To learn why, check out my article on why do turtles need a heat lamp?
What Temperature Is Too Cold For Turtles? Too Hot?
Basically, try to follow the following rules of thumb:
- Try to get the basking temperature anywhere from 80 degrees to the low 90 degrees Fahrenheit.
- If the temperature is too hot, you’ll know because your turtle will avoid the basking spot. It may also only stay underneath your light for a few moments before getting into the water again.
- If you can, try to check the temperature of your basking spot. Check it directly in the center of your basking spot’s surface.
- If you don’t have a thermometer to check, estimate, as best you can, the distance between your basking spot and your UV-B bulb. For 100-watt bulbs, you need to place it at least 12″ inches or so away. For smaller bulbs (50 to 75 watts), it will be a little bit closer.
Summary
In order to meet your red-eared slider lighting requirements, make sure that:
- The basking temperature is anywhere from 80 degrees to 94 or so degrees Fahrenheit.
- You have a UV-B producing light-bulb.
