A turtle tank with slightly cloudy water

Why Is My Turtle Tank Water Cloudy? Causes, Fixes & More

Figuring out why your turtle tank is cloudy can be all-consuming. As a responsible pet-owner, it’s only natural to want to figure out what’s going on.

This guide will teach you why it’s happening, and if it’s even something you should be worried about at all!

Why Is My Turtle Tank Cloudy?

As a turtle owner, you try your hardest to give your pet the best food, the nicest tank enhancements and the cleanest, healthiest tank conditions. But what if one day you find that your turtle’s tank is full of cloudy water?

Should you be worried? Are you doing something wrong?

In most cases, a cloudy tank is nothing to stress over, and this condition will almost always clear up in a few days. Most of the time, you don’t need to do anything drastic to get rid of the cloudy water, but there are times when intervention may be necessary. It all depends on the actual cause of the cloudy water. To help you figure out why your turtle tank is cloudy, we’ll go over a few of the most common reasons.

1. New Tank Syndrome

If you have recently set up a new tank or have replaced more than 25 percent of the water in your turtle’s tank, then this is probably the cause of the cloudy water. Commonly known as new tank syndrome, this initial water issue is a very normal part of creating your turtle’s new environment.

To understand the theory behind what’s going on in your turtle’s tank, you need to have a working knowledge of something called the nitrogen cycle. While this may seem kind of technical, understanding every aspect of your turtle’s environment will help you to become a responsible and savvy turtle caretaker.

A turtle tank with slightly cloudy water

The basic gist of the nitrogen cycle is that things like your turtle’s waste material, food particles and dead plant matter can cause a dangerous build up of ammonia in the tank. The beneficial bacteria that live in your tank’s filter break down the ammonia into nitrite. The nitrite gets turned into nitrate, and this nitrate is either removed by live plants in your tank or through periodic water changes. This whole cycle keeps repeating as long as all of the components are working properly.

When you set up your tank or change out a lot of the tank’s water, the bacteria that deals with the buildup of ammonia won’t have had enough time to become established. For a while, the amount of ammonia in the water will exceed the population of beneficial bacteria. However, once the bacteria begin to reproduce, their population will “bloom” in proportion to the amount of ammonia in the tank. This bacterial “bloom” will cause the water in the tank to appear cloudy.

Expert Tip: This condition almost always clears up on its own, so just be patient and let the cycle adjust itself. Don’t be tempted to replace the water, or you’ll be dealing with more cloudy water in your turtle tank as the system tries to reach equilibrium.

2. Turtles Are Messy Eaters

Pieces of your turtle’s food that are left in the tank could be the cause of cloudy water. If you feed your turtle in its tank, then food waste could definitely be the culprit. Turtles are notoriously messy eaters, and the water in the tank can quickly become full of uneaten food, bits that are spit out and other partially eaten pieces.

A good sign that food particles are causing the water to appear cloudy is if the cloudiness is accompanied by a bad odor, or there is a noticeable film on the surface of the water. This build-up of particles in the water can harm your turtle, so the tank will need to be properly cleaned as soon as possible.

3. It Could Be The Filter

Another likely cause of cloudy water in a turtle tank is related to the filter. When we talk about the tank’s filter in this section, we’re referring to the filter canister and other associated parts. We are not talking about the filter media because this is where the beneficial bacteria live and cleaning it will kill the bacteria.

The trick is to find the right balance between cleaning the filter too often and not cleaning it often enough. If you don’t clean the whole filter system at least once a month (we recommend a bi-monthly cleaning) then there is a good chance that there will be a dangerous build up of waste in the tank. On the other hand, cleaning the system too often may kill off some of the beneficial bacteria in the tank, and then you’ll be back to square one again.

Expert Tip: Other filter issues that can cause cloudy water include using the wrong type of filter for the size of the tank and not using a filter meant for turtle tanks.

4. Know Your Chemistry

Maintaining the proper environment for your turtle is all about balance. The chemicals inside the tank are a very important part of this balance. If even one of the parameters of the tank is off, then you may experience cloudy water in the turtle tank. There are ways to prevent this, and we’ll discuss them a little later.

5. Be Careful With Your Substrate

There are several types of substrates that are fine to add to your turtle’s tank. Pebbles, aquarium gravel, crushed coral and fluorite are typically all acceptable substrates.

Whichever substrate you choose, it’s very important to give it a good rinse before you add it to your turtle’s tank. Most substrates are coated in dirt and dust when you take them out of the package and simply dumping them into the tank will cause the water to become cloudy and dirty.

6. It Must Be Something In The Water

The kind of water that you use in your turtle’s tank is very important. When it comes to filling up the tank or rinsing filters, not all water is created equal.

Tap water, while convenient, is the worst type of water to use in your turtle tank because it’s usually treated with both chlorine and fluoride. Chlorine is not only hazardous to your turtle, but it will kill off all of the beneficial bacteria that colonizes the filter media. Once this happens, you’ll have to deal with new tank syndrome until the system comes back into equilibrium.

7. Algae Blooms

Algae, a common scourge of many turtle tanks, is often the culprit when it comes to a cloudy tank. If you feed your turtle in the tank, overfeed your turtle, or skip a cleaning, then you run the risk of setting off an algae bloom.

Algae feeds on a turtle’s waste and on bits of food scraps left to rot in the tank. When the tank becomes full of this material, the population of algae will “bloom”, thereby causing a cloudy turtle tank. Cleaning your tank on a regular basis, feeding your turtle outside the tank and using a UV light may help to minimize algal growth.

8. It Could Be The Tank Decorations

Have you recently added some new decorations to your turtle’s tank? If so, then this could be causing cloudy water.

Tank decorations (especially driftwood) can discolor the water in a tank. Placing a piece of driftwood in the tank without soaking it ahead of time will cause dirt and tannins to seep into the water. Not only will tannins cause unsightly clouding, but they will lower the pH of the water.

9. Too Much Light

While you want your turtle’s tank to have sufficient lighting, it is possible to have too much of a good thing. If you have the tank in a sunny spot in your home, or if you have very strong tank lights, then you could be inadvertently causing an algae bloom and cloudy water. Too much light will make algae grow faster than the filter can deal with it. Moving the turtle tank to a less sunny area and setting up dimmer lighting may help.

How To Fix A Cloudy Turtle Tank

As we mentioned above, having cloudy water in your turtle’s tank is usually nothing to worry about. However, it can still be upsetting and frustrating, especially if it’s the first time that it’s happened.

There are a few things that you can try to clear the water faster, but they are not guaranteed to work every time. Let’s go over a few of these methods, and you can try them out for yourself.

Don’t Do Anything

This may seem counterintuitive, but it’s often best to simply let the environment in the tank sort itself out. This is especially true if you think that you could be dealing with new tank syndrome.

Try A Water Conditioner

Sometimes using a dissolvable water conditioner can clear up cloudy water in a turtle tank in a shorter period of time. Water conditioners work to get rid of any chlorine or ammonia that may be causing cloudy water. Many of these conditioners even have starter cultures of bacteria that help to speed up the process.

This doesn’t always work, but it can be a good way to ensure that your tank water is free of chlorine.

Air It Out

Many people find it very helpful to use an air pump in their turtle’s tank. The idea behind this is that the air pump will improve the quality of the water, add more oxygen to the water and will help to speed up the growth of beneficial bacteria. A healthier and more aerated tank may mean that the cloudy water in your turtle tank will clear up a bit faster.

Keep That Filter Clean

If you’re noticing that your turtle tank has cloudy water that isn’t going away, then you may want to give your whole filter system a good cleaning. That means cleaning the canister, tubing and other parts.

Expert Tip: Don’t clean the filter media in running water because this is where the good bacteria live. Instead, keep it in a little tank tank water during the cleansing process.

How To Keep Turtle Tank Water Clear

If you have a turtle, then you can expect to experience cloudy water in its tank at least once. However, there are things that you can do to minimize the chances of recurring episodes.

Most of these tricks are fairly simple steps that any turtle owner can take, so let’s go over a few!

A turtle that's swimming in water that has been clean

Let Your Turtle Dine Out

A big mistake that rookie turtle owners make is to exclusively feed their turtle in the tank. Turtles are very messy eaters, and food particles left in the tank can quickly lead to a dirty tank and cloudy water.

To avoid this, you can place your turtle in a separate tank or in a feeding tub for mealtime. This way your turtle’s tank stays free of food waste, and less mess in the water means cleaner and clearer water.

Go Easy With The Water

An important thing to remember when changing out the water in the tank is that you shouldn’t go overboard. With each water change, you should only be removing about 25 percent of the water. Don’t forget that the tank water contains lots of helpful bacteria, so removing too much of it can lead to issues.

If you have set up a new turtle tank and find that the water becomes cloudy, don’t be tempted to dump out all the water and start from scratch. This will only lead to more cloudy water. Wait it out, and the water should clear up.

Stick To A Cleaning Schedule

Maintaining a consistent schedule for cleaning the filter is very important. We recommend taking apart and cleaning the whole filter at least once a month.

Expert Tip: Remember to keep the filter media in some tank water, so you don’t kill off the good bacteria. Never clean the filter media in tap water.

Invest In A Gravel Vacuum

We like to use a gravel vacuum because it sucks up all of the gunk that gets trapped under the substrate. The tank’s filter can only do so much, and it is often not powerful enough to filter out all the stuff that’s hiding under the gravel.

Not only will this accumulated junk cause cloudy water in the turtle tank, but it can also be very bad for your pet’s overall health.

Add Some Fish

There are some species of fish that are known to help keep a turtle’s tank a little cleaner. Species like ghost fish, catfish, and plecos, are a few of the most common cleaners. Because fish add ammonia to the water, it’s important to only add a few and to monitor the ammonia level. Not only is this ammonia bad for your turtle, but too much ammonia will kill off all of the fish.

Expert Tip: Since some turtles love to eat fish, provide your helper fish with plenty of places to hide. Stay away from spiky or armored fish because they may hurt your turtle.

Try A UV Sterilizer

UV sterilizers can be a helpful tool because they’re designed to kill off the algae, bad bacteria, and viruses that may be causing cloudy water. This type of sterilizer should be kept on all day long for the best results.

Give Your Turtles Their Own Space

If you have more than one turtle, you may be tempted to place them in the same tank. We recommend keeping turtles in their own separate tanks. When you house turtles together, the waste is often just too much for the filter to handle. Also, the amount of ammonia in a multi-turtle tank can reach dangerous levels.

Activated Carbon May Do The Trick

Adding activated carbon the the filter media is known to reduce the instances of cloudy water in turtle tanks by filtering out tannins and other chemicals from the water. Using activated carbon may reduce cloudy water and lengthen the time between cleanings.

Seed The Water

Seeding the water is an excellent way to keep your turtle tank as clean as possible. It involves taking plants, decorations, substrate, and water from a tank that is already established and adding it to a new tank set up. When you transfer things from an old tank into a new one, you are also transferring a nice colony of beneficial bacteria. Seeding the water may cut the stabilizing time in half.

Miscellaneous Things To Try

Some other things you can try include using bacteria supplements, closely monitoring the temperature inside the tank and investing in a chemical test kit.

Why Clean Water Is So Important

Making sure that the turtle tank has clean water is an important part of keeping your turtle happy and healthy. As we discussed above, a little cloudy water in the tank is normal and is usually a temporary condition. What we’re talking about is a tank that has scummy water, algae or slime on the glass or just visibly dirty water.

Your turtle needs water that is free of excess ammonia, chlorine, turtle waste and food particles. In the same way that you would not want to swim in a pool that was dirty, full of trash or high in harsh chemicals, your turtle doesn’t want to live in a tank that makes it feel uncomfortable or that could make it sick.

Dirty tank water can cause your pet turtle to develop potentially serious conditions such as shell rot, shell infections, eye infections, respiratory infections, and pitted shells.

Your turtle depends on you for its overall quality of life. Remember that once you take a pet turtle into your home, it becomes part of your family. Take the time to properly clean your turtle’s tank on a regular basis and closely monitor the pH of the water as well as the level of all potentially harmful chemicals.


Now that you have some possible reasons why your turtle tank is cloudy, it’s time for you to look and diagnose the problem.

Remember, don’t rush to take action if it’s not necessary. Sometimes that can do more harm than good!