How to Clean Your Red-Eared Slider Turtle Shell? [Step-by-Step Guide]

Some people may assume that a turtle’s shell will need to be cleaned regularly, but this is not always the case. If their enclosure is cleaned and maintained regularly, their shells will not require cleaning. If a turtle’s shell is unclean and needs good scrubbing, this is usually a sign of an unhygienic habitat that has hard water or excessive algae. In some circumstances, a dirty shell could be a sign of something more serious like shell rot.

How to Clean Your Red-eared Slider Turtle's Shell

Red-eared sliders are an ideal species of turtle to keep as a pet and can live up to 40 years with good care. Fortunately, these turtles don’t mind being handled, so cleaning their shell should not be too much of a hassle.

Owning a turtle is a big commitment, as you will need to be aware of the warning signs of a dirty tank or health issue. You have come to the right place, because we have the best tips to clean your red-eared slider’s turtle shell and how to avoid cleaning it again in the future!

How Often Do I Need to Clean My Turtle’s Shell?

It is not required to clean a turtle’s shell unless it is looking particularly dirty. If their habitat is cleaned efficiently and regularly, their shells are basically self-cleaning due to moving water that is regulated with a good filtration system.

They will only need a good scrub if there is a buildup of algae, if there seems to be a scratch or cut, or if there are any white or soft spots on the shell.

Also Read: Can Turtles Feel Touch on Their Shell?

How to Clean Hard Water Spots on a Red-Eared Slider Shell?

Hard water in a tank or aquarium is fairly obvious to spot. The turtle’s shell will look slightly dry and dusty, kind of like a layer of chalk.

This may look like your turtle is sick, but is actually harmless to them and can be cleaned off easily. This dryness is caused by the residue from dissolved minerals as a result of hard water.

In North America, most tap water is considered hard water because of the dissolved magnesium and calcium minerals. This is safe for human consumption and will not harm your turtle.

Here is how to clean hard water from a shell: 

  • Mix a bowl of distilled water with a few tablespoons of apple cider vinegar.
  • Mix this concoction with an old toothbrush – make sure the bristles are softened.
  • Make sure your turtle is dry from their aquarium.
  • Gently brush the water and apple cider vinegar mixture over the shell with the toothbrush.
  • Keep brushing every part of the shell in small circles for several minutes.
  • Let the turtle air dry.

The most important step to take prior to putting the turtle back in its tank is to gradually replace the hard water with distilled water. This has to be a gradual process to not disturb the natural ecosystem that has developed.

How to change hard water to distilled water:

You will need to temporarily keep your turtle in a separate container outside of the tank. This is a worthy purchase regardless of changing water, as it is useful for general cleaning and veterinary trips.

The best way to gradually change hard water to distilled water is by using a water conditioner. These conditioners work to eliminate the distilled minerals, and will therefore keep your turtle’s shell shiny and clean.

We recommend the Zilla Reptile Aquarium Water Conditioner, as it is an easy conditioner to use to make regular tap water a safe environment for turtles.


In the wild, it is normal to see a turtle with algae on its shell. In captivity or as a pet, it’s less common for algae to appear if the tank is properly taken care of. For a pet red-eared slider, you shouldn’t really see algae on their shell.

Some algae look green and spongy, covering the shell kind of like a carpet. Other algae often look stringy, long, and slimy – which is the worst-case scenario.

This can be a sign that the temperature of the water is too hot or cold, the filtration system may not be working, or the biological cycle of the water is not working.

It is normal to see a bit of alga in a tank from time to time, but if it features on the shell it can be an unfortunate indicator of a shell infection or shell rot – which we will talk about later.

How to clean algae from the turtle’s shell

  • In a basin or bucket, run some lukewarm water. Place the turtle in and let the water run over its shell.
  • With an old toothbrush (again, make sure the bristles are soft), gentle scrub away the algae for several minutes.
  • Be prepared for your turtle to struggle, so hold it securely.
  • Let your turtle air dry in a container or box.
  • Sanitize the basin or bucket to get rid of the salmonella bacteria that your turtle naturally carries.

How to Clean Algae from The Aquarium

Here is how to check that your tank is running the way it should be:

  • The water temperature needs to be between 76 and 85 degrees Fahrenheit.
  • The basking surface needs to be between 80 and 95 degrees Fahrenheit under a heat source such as a UVB light.
  • Check your filter – it needs to be strong enough to handle all of the water in the tank. Always go for a good quality filter that is rated at least double the gallons of water in the tank – for example, a 55-gallon tank needs a 110-gallon rated water filter. Turtles produce a lot more waste than normal fish, so the filter needs to be able to handle it. This will also create moving water, which works to wash away algae naturally.

Our top tip is to keep the tank or aquarium away from direct sunlight. Whilst turtles love the heat, this can be achieved by using a UVB light. Sunlight promotes algae growth, so if your tank seems to be working smoothly but is still growing algae, then this could be the culprit.

Shell Rot and Shell Infections

It is unfortunately common for turtles to develop shell infections and shell rot. Shell rot can be caused by several things, including:

  • A scratch to the shell
  • Poor basking areas and lack of heat
  • Terrestrial turtles such as box turtles who are exposed to too much dampness

As red-eared sliders are aquatic, the last factor does not apply to them. The most common cause of shell rot is down to a cut or scratch in the shell that is left untreated. This can occur by sharp rocks or interior items such as logs, so make sure to avoid anything with a sharp edge that could cut their shell. Their shells may seem hardy, but shell infections are common.

Shell rot is a fungal infection that, if left untreated, can be fatal. The main symptoms of shell rot include pale or white patches across the shell, areas of softness, or indentations in the shell.

This can be really uncomfortable for the turtle, so be sure to become aware of what looks normal and abnormal in your turtle’s shell. Skin fungal infections also look similar to this, as the skin will go from the natural brightness to dull or white patches that look sensitive.

How to Cure Shell Rot

You will need a bottle of betadine or povidone-iodine 10% solution, a container, tissues, and Q-tips. As shell rot is sensitive, even an old and soft toothbrush is too harsh.

  • Air dry your turtle in a separate container (physical drying them with a towel will irritate the infection).
  • With a Q-tip, take your chosen betadine or povidone-iodine 10% solution and gently rub it over any infected areas. It is worth spreading the solution around the area of the infection just to be on the safe side.
  • Stay away from their head and especially their eyes, ears, and mouth.
  • Place the turtle back in its container underneath a UV light, so it can bask there for a few hours. This is to allow the solution to set into the infection without washing away in the water.
  • Your slider will want to go back into the water after this, but only let them in for an hour at most. It is not recommended to put them back in their aquarium, as this will wash away the solution.
  • If the infection is shell rot, keep the turtle in a separate container with no water for the majority of the day.
  • Repeat this daily until the infection has disappeared.

If the infection has remained after a week of this cleaning routine, you will need to immediately take the turtle to the vet. They will offer a stronger medication and treatment for the rot.

Metabolic Bone Disease

It is normal for younger turtles to have softer shells, as these will strengthen over time. For adults with slightly softer or weaker shells, this could be a sign of something more serious.

Metabolic bone disease is when a turtle’s shell grows at a disproportionate rate compared to the rest of its body. The symptoms of this include:

  • Softened shell
  • Depressed or indented shell
  • Malformed shell
  • Curling of marginal scutes
  • Trouble walking, or dragging itself

This is caused by an unbalanced diet that usually lacks calcium or vitamin D. If your turtle is not basking, they are most likely not taking in the essential vitamin D, that will need to be supplemented in their food.

This could also be a sign that the UVB light is not warm enough or is blocked by glass, which will need to be removed. Calcium can be supplemented too, which will be explained later.

Metabolic bone disease can be fatal if not treated properly and is incredibly uncomfortable in the meantime for the turtle. If you notice anything abnormal about the shell, take your turtle to the vet immediately.

Keeping the Turtle’s Shell Healthy

A healthy turtle shell all comes down to keeping on top of general maintenance and the turtle’s diet. Whilst products online and in pet stores are designed to treat the problem, whether it is shell rot or algae, they will not work to prevent it.

Remember, the turtle’s shell needs to be naturally hydrated and somewhat left alone, so these ointments can actually trap bacteria in the shell to stop it from breathing.

For aquatic turtles, their aquarium will need to be cleaned thoroughly once or twice a month. Terrestrial turtles will only need their terrarium to be cleaned once every few months. Staying on top of this cleaning process is paramount to the health of your turtle and its shell.

For a red-eared slider, they will need a tank of at least 80 gallons – anything smaller will be too restricting and will promote bacterial growth.

There needs to be a dry basking area with a temperature from 80 to 95 degrees Fahrenheit underneath a UV light – this heat source replicates the rays and warmth from the sun that is vital for reptiles to regulate their body temperature.

It is recommended to update this UV light every year to prevent a fault heat source.

The filtration system is really important for maintaining the turtle’s waste and keeping the water moving. This system needs to have a mechanical, biological, and chemical cleaning system to prevent algae growth and to control hard water from affecting the turtle’s shell.

How a Turtle’s Diet Will Affect Their Shell

The turtle’s diet is really important to keep their skin, muscles, bones, and shell healthy. Red-eared sliders are aquatic turtles, so there is always a chance that they will avoid or forget to bask. They will need a sufficient amount of vitamin D that they will be lacking from the UV light source.

However, this should only happen if they are not basking enough because an unnecessary and excessive amount of vitamin supplements can be counterproductive.

As explained before, a lack of calcium can be a reason for metabolic bone disease. To supplement this, you should feed your turtle leafy greens such as dandelions, mustard, or calcium supplements. As with humans, calcium helps to build strong bones, and therefore shells, which will improve the quality of the turtle’s life greatly.


So there you have it! You do not need to clean a turtle’s shell if it looks normal, as this is a sign that they are happy in their functioning habitat. However, anything that looks abnormal is most likely a sign that their environment needs cleaning or water replacement.

An unclean shell can also, unfortunately, be a sign of a disease or infection that has the potential to be fatal, so it is always worth checking any abnormalities with a vet.

Dorothy Razo

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