Why Does My Turtle Tank Smell? 8 Causes & Solutions

As a turtle owner, it's natural to wonder why your turtle tank might have an unpleasant smell. Many things could contribute to this issue, and understanding them will help you maintain a healthy environment for your shelled pet.
Why Does My Turtle Tank Smell Bad?

We will explore the reasons behind a smelly turtle tank and provide you with some practical solutions to the problem.

By following the advice and tips provided below, you’ll be well-equipped to tackle the issue of a smelly turtle tank and ensure a comfortable home for your turtle.

Why Does My Turtle Tank Smell Bad?

Turtle tank smell can often be attributed to a few common culprits. Leftover food, feces, and poor water quality are some of the primary causes.

If you don’t clean your turtle tank regularly and neglect water changes, it can lead to the buildup of waste and bacteria. This can not only cause unpleasant odors but also be harmful to your pet turtle’s health.

Inadequate filtration is another reason why turtle tanks can start to smell bad. Proper filtration helps maintain a healthy environment for your turtle by removing waste particles and chemicals.

Using a high-quality filter ensures that uneaten food, feces, and other waste materials do not accumulate and cause the tank to stink.

8 Turtle Tank Stink Causes

There are a few reasons why your turtle tank has a dirty appearance and an unpleasant smell.

1. Algae

Algae can cause odors in turtle tanks due to the decomposition of organic matter present in the algae. As algae grow and die, they release organic compounds that can break down into ammonia, nitrites, and nitrates.

These compounds can then react with other chemicals in the water to produce unpleasant odors.

Some algae in the tank is actually a good thing, but you don’t want to let overrun the tank.

You might be able to keep fish with your turtle (depending on the species of turtle you have) if so I have a post of the best algae-eating fish you could add.

2. Ammonia

NH3 Chemical Symbol For Ammonia

Ammonia is a large factor in turtle aquarium odors, as it is a byproduct of decomposing waste like feces and leftover food.

If not properly managed, it can build up and lead to an unpleasant smell in a turtle tank.

You need to monitor ammonia levels to protect your turtle from potential health issues and maintain a fresh-smelling environment.

The nitrogen cycle in your turtle’s tank is an important process that helps break down ammonia, converting it to less harmful substances.

3. Feces

A Steaming Turd

Feces contribute to both ammonia and bad smells in your turtle tank.

Turtles produce a significant amount of waste, and it is essential to clean it regularly to prevent issues with water quality and odor.

Decomposing poop releases ammonia into the water.

4. Left Over Food

Turtles are super messy eaters and don’t eat every last morsel of what you feed them.

It’s a bit like a dog who will happily eat the large cookie you give them, but then leaves crumbs all over the floor.

Leftover food will also start to break down and release ammonia into the water.

5. Filter Too Small

Turtles produce a lot of mess, so you’re going to need a heavy-duty filter to deal with all that mess.

If you’ve got a filter based on the size of your turtle aquarium, you need to get a bigger filter.

I’ve left more information on this further down this post.

6. Lack Of Tank Maintenance

If you let all of the above accumulate your tank water will go stagnant in no time.

Stagnant water in a turtle tank creates an environment where anaerobic bacteria thrive, which can produce foul-smelling gases like hydrogen sulfide and make your turtle tank smell like rotten eggs.

7. No Basking Area

Turtles, being cold-blooded, rely on their surroundings to regulate their body temperature.

They swim to cool off and bask in the sun, or under a heat lamp, to warm up.

Basking also helps them absorb vitamin D3, essential for maintaining healthy shells and bones, and for drying their shell off, preventing fungal infections and algae growth, which can cause your turtle to smell.

8. Shell Rot

Turtle With Shell Rot

If your turtle has to live in dirty water and doesn’t have access to an adequate basking area, he or she may develop shell rot as a consequence.

The infection can cause the turtle’s skin and shell to become soft and mushy and as the shell’s tissue decays, it can release foul-smelling gases that contribute to the smell.

If you suspect your turtle has shell rot, it’s important to seek veterinary care as soon as possible to prevent the infection from spreading and causing further damage.

You can find your nearest turtle vet on the Association of Reptile and Amphibian Veterinarians website.

How Do I Get My Turtle Tank To Stop Smelling? 8 Easy Solutions

There are several things you can do to get rid of the smell in your turtle tank.

1. Keep Your Turtle In The Correct Sized Tank

To prevent smells, start by selecting an appropriately sized tank.

Many people start off with a 20 or 40 gallon tank, which is OK for a juvenile turtle, but they quickly outgrow this size of tank.

When it comes to getting the size of the tank right, the rule of thumb is to have a tank of at least 10 gallons per 1 inch of turtle shell carapace length.

Red Eared Slider With How To Measure A Turtle Shell Carapace Length

There should be enough water depth to allow your turt to be able to rotate fully, nose to tail, without catching on anything.

An adult red-eared slider needs a tank of at least 70 gallons.

A larger volume of water takes longer to get dirty and start to smell like rotten eggs.

If the tank is too small, the water in the tank will get dirty and smelly much faster.

If you need to get a bigger tank, I have some great options in my best tank for red-eared sliders post.

2. Adequate Water Filtration

You need a high-quality filter for your turtle tank.

Aquarium filters are rated for the volume of water in fish tanks, and fish don’t produce anywhere near the amount of waste that a turtle does.

Turtle tanks need a filter rated for at least 2-3 times the volume of water in the tank.

A 70-gallon turtle tank will need a filter along the lines of a Fluval FX4.

I’ve listed the best filters for turtle tanks so you can keep your tank water clean and odor-free.

3. Setup A Basking Area

Setting up a basking area for a turt is straightforward.

A basking platform is essential for their health and helps prevent algae and fungus from growing on your turtle.

You’ll need the following:

I have a complete guide that shows you how to set up a turtle tank

4. Regularly Clean The Tank

Cleaning A Turtle Tank

Cleaning your turtle tank regularly is essential for reducing smells.

You should perform some maintenance on your turtle tank daily. A great routine to set is:

Daily Remove any visible poop, leftover food, and other gunk
Weekly Replace at least a quarter of the water to lower ammonia, nitrite, and keep the nitrate levels below 40 ppm
Monthly Perform a deep clean of your turtle tank and filter

Don’t forget about cleaning other tank components like the basking area.

This guide on how to clean a turtle tank will help you keep the tank clean and maintain a healthy environment for your pet.

5. Plants

Including live plants in your turtle tank offers not just aesthetics but also additional benefits.

Plants help absorb toxins, reduce algae growth, and provide hiding spaces for your turtles.

Aquatic plants can help minimize smells while improving the overall water quality in your turtle tank.

I have left a list of the best plants for a turtle tank here.

6. Remove Any Uneaten Food

Leftover food particles in the water aren’t good as they will break down and release ammonia.

Supervise your turtle while it’s eating and clear up any bits of food that aren’t eaten, to prevent rotting.

A small fish net is great for larger bits and a turkey baster is great for sucking up those annoying small floaty bits of detritus.

3" Fish Net
Turkey Baster

7. Feed Your Turtle Outside Of Their Tank

You may consider using a separate feeding container for your turtle to minimize the amount of uneaten food and feces in the main tank.

Your turtle will poop and pee whilst eating, it’s natural for them to do so.

Any leftover food, poop, and pee will be kept in the tub you’ve fed your turtle in, rather than being left to fowl up the tank water.

8. Water Treatments

There are 5 water treatments you can use to help keep your water clean and safe for your turtle.

1. API Accu-Clear

API Accu-Clear

Use API Accu Clear if you need to fix cloudy turtle tank water.

It works by making tiny particles of waste matter clump together so they drop to the substrate to then be removed by your water filter.

Add 1 ml per 10 gallons of tank water once per week, or whenever your water goes cloudy. 

2. API Turtle Sludge Destroyer

API Turtle Sludge Destroyer

API Turtle Sludge Destroyer helps break down organic waste and reduce the buildup of debris on the tank bottom.

By using this product you can further prevent unpleasant smells and improve water clarity.

Just add 1 tsp/5ml per 10 gallons of aquarium water on a weekly basis.

3. API Turtle Water Conditioner

API Turtle Water Conditioner

API Turtle Water Conditioner removes chlorine and chloramine from your tap water making it safe for your turtle to swim in.

Although turtles aren’t as sensitive to chlorine and chloramine as fish are, it’s still not good for them.

Add 1 tsp/5ml per 10 gallons of tank water when setting up a new turtle tank or performing water changes.

4. Flukers Eco Clean

Flukers Eco Clean

Fluker’s Eco Clean is another beneficial bacteria-in-a-bottle product designed for use in turtle tanks.

It breaks down waste matter and prevents/removes foul odors from the tank water.

The first-time dosage is 10 ml per 10 gallons (38 liters) of tank water. 

You then maintain the product by adding 5 ml per 10 gallons (38 liters) of tank water once a week.

5. API Turtle Fix

API Turtle Fix

API Turtle Fix contains Tea Tree oil, a natural ingredient that effectively treats topical bacterial infections and wounds on your turtle.

For 7 days straight add 1 tsp/5ml per 10 gallons of aquarium water. After 7 days, perform a 25% water change.

By following these tips and guidelines, you can keep your turtle tank smelling fresh and create a healthy habitat for your pet turtle.

Why Is My Turtle Tank Cloudy And Smelly?

A cloudy and smelly turtle tank can happen for several reasons. One common cause is waste accumulation from turtle feces, uneaten food, and decaying plants.

Excessive algae growth can also contribute to cloudiness and odor. To maintain a clean and healthy tank, ensure you are filtering the water effectively, removing debris, and avoiding overfeeding your turtle.

Newly set up turtle tanks may suffer from new tank syndrome, resulting in bacterial bloom and cloudy water.

Failing to fully cycle the tank before adding the turtle can cause this. The water should clear up naturally within a few weeks once beneficial bacteria have colonized the tank.

If your tank has been set up for a while, chances are it is poor tank maintenance or a dirty or underpowered filter that is causing the cloudy turtle tank water.

Why Does My Turtle Tank Get Dirty So Fast?

Turtle tanks can become dirty quickly due to their inhabitants’ messy habits and rapid waste production.
Turtles are known to be messy eaters, often leaving uneaten food to decompose in the water.

To minimize how rapidly your tank gets dirty, keep your turtle in a large enough tank, invest in a quality filtration system, conduct routine water changes, and clean your tank regularly to eliminate potential sources of waste.

Closing Thoughts On Why Does My Turtle Tank Smell?

Now you understand the reasons for the unpleasant odor in your turtle tank and know how to fix it, you can sit back, relax, and breathe in the fresh-smelling air!

To recap the key points:

  • Make sure the size of your tank is suitable for the size of your turtle
  • Remove any leftover food after feeding, or feed out of the main tank
  • Perform some cleaning on your tank every day
  • Perform a 25% water change on a weekly basis
  • Deep clean the tank as often as once per month
  • Get a suitable filter
  • Provide a basking area
  • Add some plants
  • Use water treatments

Following the above steps will stop your turtle tank from developing a foul smell odor and swamp-like appearance.

Check out the turtle section for more guides on keeping your pet turtles happy and healthy.



Hey, fellow fish enthusiast 👋! I'm Paul and I've been an aquarium addict since I won my first goldfish at the fair many years ago. Let me share with you the knowledge that I've gained along the way (and avoid the mistakes I've made!), so you too can create an underwater paradise for your aquatic friends.