Substrate is whatever you put on the bottom of a turtle tank or tub. It can be anything from sand, gravel, wood shavings, etc. The most common type of substrate in turtle tanks is rocks.
Rocks for turtle tanks are available in many shapes, sizes, materials and colors. It is important that you choose ones that will look great in your tank, but also be safe for your turtles.
Royal Imports River Rocks ~$15
Royal Imports River Rocks are the best rocks for turtles because they come from actual rivers. They are also too big for your turtle to swallow.
In today’s article, I will review the best type of rocks for a turtle tank, and discuss some guideline that should help keep you turtle safe and healthy.
Best Rocks for a Turtle Tank
The best rocks for a turtle tank are the Royal Imports Decorative Rocks and the Aquarium Gravel River Rock. Both add great aesthetics to your tank without causing a hazard for your turtle.
Below is a review of both types of rocks. Both can be purchased on amazon.
Royal Imports Decorative Rocks
The Royal Imports rocks are my favorite. They are what I used in my tank for my turtles. They are the best priced rocks you can find on Amazon, as they only cost ~$16 for 5 lbs.
As you can see from the picture above, they come in a variety of colors and shapes. This helps give your turtle tank a great, natural aesthetic. They are also very smooth so you don’t have to worry about the rocks scratching your turtle or the glass on your tank.
It is important that you select the “Large” option when you order these rocks. If you accidently order the “Small” rocks, your turtle might try to eat them.
Even though the rocks should be clean, I do recommend that you wash them before your put them in your tank. The easiest way to do this is to put them in boiling water for 10 minutes.
Aquarium Gravel River Rock
Aquarium Gravel River Rock is also a great option for your turtle tank. Since these rocks are a bit smaller than Royal Imports, I would suggest only using these stones if your turtle is 5 inches or less. You might still need to remove some of the smaller rocks in the bag if you think your turtle might eat them.
These rocks are a little more expensive (~$28), but they come with around 18 lbs and offer a beautiful array of colors. I will say that they aren’t as smooth as the Royal Imports, but they are not sharp enough to cut your turtle or scratch your glass tank.
If you have a 50-75 gallon turtle tank, you will likely need to buy 2 bags.
Now the two rocks I recommended are for aquatic turtles. If you have a box turtle, you should check out my article on the best substrate for box turtles.
Are rocks a good substrate for turtle tanks?
This is a heavily debated topic, but I will say rocks are a good substrate for turtle tanks as long as the rocks are bigger than your turtle’s head. If you put in small rocks or pebbles, there is a chance your turtle will eat the rock. Below I will list all the pros and cons of putting rocks in your turtle tank.
Pros of putting rocks in a turtle tank:
- It looks nice and is more natural for your turtle.
- They can hold beneficial bacteria on its surface, which helps with filtration.
- Allows turtles to search and forage through it for good.
- Doesn’t clog up your filter like sand.
- Will not trap as much debris as smaller substrates, which will help keep the water cleaner.
Cons of putting rocks in a turtle tank:
- The biggest cons of rocks is that your turtle might eat it. If they ingest a rock, it could cause a blockage in their stomach called an impaction, which can lead to throwing up and even death.
- Rocks can hold a lot of waste (uneaten food, poop, etc.) when it falls to the bottom. You will probably have to clean it more often than if you didn’t have any substrate. For tips on cleaning, check out my article on how often to clean a turtle tank.
How much rocks do I need for my turtle tank?
This is a tricky question, because it depends on the size of the rocks. You will likely need 20-25 lbs of rocks to cover a 75 gallon turtle tank. However, you don’t need to cover the entire bottom if you don’t want to.
In the area where you do put the rocks, I would suggest having around 2-3 inches worth that covers the bottom. Depending on the size of the rocks, this could be 1 to 2 layers.
Aside from rocks, you should check out my guide on other important turtle aquarium accessories.
Can I put rocks from outside in my turtle tank?
Yes, you can put rocks from outside in your turtle tank. However, it is mandatory that you clean them before you put them in. I suggest that you first rinse off the rock, and then put it in boiling water for 20 minutes. Do not put any soap on the rock.
You should try to select stones that are smooth. You will not want any sharp or rough edges on the rocks because these could hurt your turtle if they get a scratch or cut from the rock. A sharp rock can also scratch the glass on your tank.
What size rocks should I put in my turtle tank?
If you want to use rocks as a substrate, you must make sure that the rocks are bigger than your turtle’s head. Any rock that is smaller than your turtle’s head might be eaten by your turtle, which can make your turtle really sick and even cause them to die.