
Aquatic turtles live in lakes and ponds with thick vegetation, growing on substrates, like sand, small stones, and large rocks. Rocks can create a rich aesthetic experience in your turtle tank. However, do turtles need a rock to sit on?
Turtles use large rocks for basking in the light. Stones in the water also give them spaces to hide, rest from swimming, or find amusement. Some turtles might even snack on the rocks in the turtle tank if they are craving minerals.
There are some details that you need to keep in mind when choosing a rock for your pet’s tank. Read this article to find out why turtles need rocks in their habitat. We will review the different choices of basking areas and rocks, and what you need to watch out for.
Why do turtles need rocks?
Rocks are not only a beautiful decoration for your turtle tank. They can also prove beneficial for your pet and make its habitat more natural.
Basking
Aquatic and semi-aquatic turtles spend a lot of time in the water and love taking long sunbaths, also known as basking.
Absorbing the UV-rays helps turtles regulate their body temperature by controlling blood flow in their skin and fins. Since they usually do that on a surface outside the water, rocks are great spots for a relaxing sunbath.
Resting
You can also put large rocks or smooth river stones in the tank as a substrate. That will create an area for your pet to hide or go up and down in the tank. In addition, your turtle will have a place to rest in its home.
Of course, rocks will also make your turtle’s habitat look more natural and aesthetic.
Amusement
You might see your pet playing with the rocks or digging around them. Such behavior might be caused by boredom. To solve this problem, you could increase your turtle tank’s size and complexity.
If you add more plants, rocks, and basking sites, your turtle will always have more activities in its home.
Snacking on rocks
Turtles also love snacking on stones because they crave minerals such as calcium and iron. So seeing your turtle eating rocks might help you indicate nutrition deficiency.
However, small stones can block a turtle’s digestive tract and might lead to death. To avoid that, consider the size of your pet and choose rocks larger than its head. Large smooth stones are a good choice in such cases because your pet won’t be able to bite a piece of the stone.

Do all turtle species need a rock inside their tank?
Most basking turtles like the red-eared sliders (Trachemys scripta elegans) and the painted turtles (Chrysemys picta), do not require any substrate. They can live in a tank with a bare floor and will feel comfortable.
Keeping the tank bottom free of rocks will give the turtle more swimming space. Although rocks can be a great resting place for the turtle, it will certainly not die of exhaustion.
However, you need to create a proper above-tank basking platform for the turtle to go out of the water and dry. If unable to bask, your turtle won’t produce vitamin D3, and it won’t be able to absorb calcium. That could eventually lead to Metabolic Bone Disease.
Adding rocks to your pet’s tank will also increase the complexity of their habitat. As a result, the turtles will have more activities and places to hide.
What rocks are a good choice for your turtle tank?
If you want to put a substrate in your turtle tank, you can create a gradient of pebbles of different sizes. You can also add large smooth river stones and lava rocks.
That will give your turtle spaces to hide and have its privacy. With the river stones, you can build a small hiding cave for your turtle. Make sure you use large smooth rocks that can stand stable on top of each other.
Lava rocks, on the other hand, can improve water quality. Their porous surface allows beneficial bacteria to colonize it and act as water filters.
If you want to create a healthy environment for your pet, you can attach aquatic plants to the surface of the lava rocks. However, there are a few details that you need to keep track of when placing rocks into your turtle tank.
What should you keep in mind when choosing a rock?
If you want to use stones as a substrate in your turtle’s habitat, consider a few things:
- the kind of rocks you are using
- where the rocks are coming from
Read on to find out more about the importance of these factors.
Cleaning rocks
An advantage of large rocks in your tank is that they are much easier to clean than gravel because they don’t trap waste and debris.
However, you might want to clean the substrate of your turtle’s home every two or three weeks. It is a good idea to soak rocks in soapy water. Afterwards, trim the aquatic plants and remove any algae with a brush.
Special care for lava rocks
You can buy lava rocks from any pet store. Nevertheless, you can’t put them in the turtle tank directly after purchasing. Lava rocks can be a habitat for bacteria that could harm your pets and the aquatic plants in your tank.
Make sure you clean your lava rocks with water and disinfect them before introducing them to your turtle’s home. After removing dirt from the rocks, you can boil them to kill pathogenic microorganisms.
When you place them in the turtle tank, beneficial nitrogen bacteria will be able to grow on them and filter the water from your pet’s waste.
Using outdoor rocks
Going to the nearby river and picking up some rocks for your turtle’s tank is not always a bad idea. They usually contain calcium, magnesium, and iron that might benefit your pet.
However, an excessive amount of calcium might alter the pH of the tank water. In addition, similar to lava rocks, they can also contain some harmful microorganisms.
Therefore, you need to disinfect the stones and test if they change the water’s pH. You can separate a small amount of the tank water into a bucket and let the rocks sit in it for a week. If the pH and the hardness of the water have changed, these stones are a no-go.
Which basking rock platform is suitable for your turtle species?
Small species
Every aquatic turtle needs an area to relax and get dry. Small species like the Common Musk Turtle (Sternotherus odoratus) and the Reeve’s turtle (Mauremys reevesii), for instance, can use an in-tank basking platform, made of a corner rock.
Your turtle will be able to climb on the top of the rock to lay in the light. A basking light on the side of the basking platform will create a temperature gradient in the tank that will help your turtle regulate its body temperature.
Large species
If you have a Red-Eared slider, an African Sideneck Turtle or an Eastern Box Turtle, you will need to design the basking platform according to the turtle’s large size. In this case, it would be a better idea to create an above-tank basking area that will give more swimming space to your pet.
You can either purchase a commercial platform or build your own out of a plastic box, for instance. Above-tank areas usually have a ramp for your turtle to climb out and slide back into the tank.
You can add some bricks, rocks, or wood to the box to make it look more like your turtle’s natural habitat. However, in this case, using rocks is not a must.
Summary
Turtles need a rock to sit on and bask. That way, they regulate their temperature and feel comfortable in their habitat. You can create a basking platform depending on your turtle’s size and species.
In addition, large stones can be used as a substrate in the turtle tank. They will allow your pet to go up and down in the tank, find hiding spots, rest, and find amusement. In case of malnutrition, turtles also snack on rocks to receive calcium and iron.
When choosing rocks for your turtle’s home, keep in mind that many pathogenic bacteria can live on stones and affect the health of your pet. Therefore, you need to clean and disinfect them, especially if picking them from nearby rivers.