Why Does My Turtle Tank Smell Like Rotten Eggs?

The information is current and up-to-date in accordance with the latest veterinarian research.

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I knew so little about turtle tank hygiene when I started my journey. Funny story! Suddenly, one day, the entire room started smelling like rotten eggs, and it was coming from my turtle aquarium. Soon, I became Sherlock Holmes and investigated what made my pet habitat stink this bad.

Turtles feed and excrete in the water. The uneaten food and waste accumulate on the bottom of the tank. Over time, these biological wastes decay and emit a foul odor, which can resemble the smell of rotten eggs. A filter malfunction or the use of a filter with too low capacity can also cause the habitat to smell bad.

We can not allow your turtles to stay in a smelly tank. Let me discuss the causes and solutions to a stinky turtle habitat in detail.

Key Takeaways

  • The algae outbreak in the aquarium leads to a damp smell.
  • Sludges made of food scraps and turtle wastes degrade, causing a putrid odor.
  • Regular cleanup is mandatory to maintain good hygiene in the turtle enclosure.

8 Reasons Why My Turtle Tank Smells Like Rotten Eggs

A rotten egg smell is the last thing you want in your home. In my turtle-keeping journey, I have discovered multiple probable reasons. Let’s talk about them all.

1. The Water Turned Green

If you follow my blogs, you already know how irritating I find the algae outbreak in turtle ponds. Obviously, I had no clue how to handle the algae in the beginning. So when the water turned green, I just lost my mind.

I tried to siphon water and replace it partially. But nothing seemed to work. Of course, it won’t. Algae proliferates faster than you can imagine.

Soon, my turtle aquarium started spreading a damp smell. The one you only experience when closer to an abandoned pond.

For a long period, I thought it was responsible for the putrid odor. But I was wrong.

Algae can contribute to the stinking. But there will be other factors combined that make the tank smell like a rotten egg. We will be talking about that in a second.

2. A Rich Source Of Ammonia

Ammonia buildup in the water can create a foul odor in the enclosure. As you know, turtles are not famous for maintaining hygiene. They will eat and poop in the same place. Ammonia is a byproduct of turtle waste.

Therefore, not picking up the poops and letting them sit at the bottom will only make the habitat stink.

Another reason for ammonia accumulation in the aquarium is a bacterial outbreak. Insufficient oxygen in the tank ecosystem due to filtration or other elements can be responsible for this.

See also  How To Keep Turtle Tank From Smelling? [9 Causes & Solutions]

3. What Is Rotting Inside?

In my setup, there were a couple of turtles and some live plants. So, I checked if there were any dead plants in the tank. In many cases, the putrid odor is basically the smell of plant decomposition.

Overrule this reason if your pet enclosure has no live plants. But recheck everything if you have put fish in the aquarium along with turtles. It can be a dead fish your turtles have preyed on. 

Any dead creature or plant will spread a foul odor as it degrades.

4. The Tank Looks Like A Garbage Can

Sludges are the main culprit for the rotten egg smell. All the residuals in the water stick together and form these balls. There are wastes of every kind. You will find food scraps, plant residuals, poop, shed skin, and whatnot.

If you do not throw away these sludges, they will make your entire room stink. Do not come complaining, then.

5. What Did My Turtle Have?

Turtles leave behind crumbs in the water. These food leftovers settle down at the bottom and start rotting. It explains the nasty egg smell in the water.

In case you don’t know, the meal choice does influence the tank smell. Say you feed your turtle a lot of fresh greens.

The scaps will decompose quickly, spreading a foul smell. On the contrary, processed foods degrade slowly.

But hey! Do not switch to a processed or commercial meal plan just for the sake of hygiene. Fresh greens are the best additions to turtle diets.

6. Too Many of Them Are There

Sometimes, we just overestimate the pond or tank we build and end up overcrowding the habitat. Only 2 to 3 small turtles can thrive in a 120-150 gallon aquarium. But we put more than 3.

Remember, it is not healthy at all.

The more the creatures inside the water, the filthier it will get.

Let’s face it.

More poop. More food scraps.

It means there will be more sludges in the tank.

As a consequence, there are more chances that the habitat will stink like a rotten egg.

Don’t get me wrong. This implies other elements in the tank, too. For example, if you plan to raise fish and add plants, you will need a bigger space. Fitting everything in the small aquarium will again crowd the habitat and lead to a foul odor.

7. You Suck at Maintaining Hygiene

What happens if you do not change the turtle tank water for months? The leftovers and poop will accumulate along with the algae outbreak. It justifies the nasty smell in the air.

Uncleaned habitat is not only responsible for the foul odor but also causes infectious diseases in the pets.

8. The Filtration System Is Outdated

Installing just any filter will do no good to the turtle habitat. Instead, aim for a quality and suitable filter system for the pet’s tank.

Setting up a filtration media with low capability can not process the generated filth. As a result, you will see no progress in water hygiene, and the foul smell will still be present in the tank.

Sometimes, the filter malfunction and basket clogging can lead to a stinky odor in the habitat.

See also  Can Turtles Smell Underwater?

turtle tank smell causes & solution: infographic

Want to get a printable version of this infographic? Click here!

7 Troubleshooting The Putrid Odor Of My Turtle Tank

Do not stress over the nasty smell in the turtle habitat. This is not permanent. Restoring the hygiene in the pet’s tank is possible with small changes. Such as,

1. I Bought A UV Sterilizer

As mentioned, an algae outbreak in the turtle habitat was not directly behind the rotten egg smell. But it was an important factor I could not overlook.

When I asked around experts, they told me to rearrange the setup location. Apparently, direct sunlight, a moist environment, and 12 to 15 hours of UV light exposure boost the algae population.

I could not compromise the moisture (turtles live in water). Nor could I limit the UVB rays (insufficient UVB leads to MBD and abnormal reptile growth).

My turtle aquarium was right beside the window. So, I installed heavy curtains to restrict direct sunlight as much as possible. It also allowed me to offer sunlight to my pets whenever necessary.

Besides, I installed a UV sterilizer that slowed down the algae growth in the aquarium.

2. Poop Maintenance Is Necessary

Turtles release both poop and pee. Their wastes are slimy, solid, and easily detectable. Just to avoid the ammonia buildup, I usually perform a regular cleaning session.

I take a net and remove the poop pieces from the water. No waste means no bad bacterial growth or rotten egg smell in the room.

3. Remove The Dead Body! NOW!

As any living body decomposes, it spreads a stomach-sickening smell. It is too much to stand.

Just take a peek into the turtle’s enclosure and see if everything is fine and alive. Throw away the dead plant roots or leaves if there are any. The dead fish are also of no use.

However, it is also possible that your turtle has passed away. It is no surprise, especially if the pet is old or suffering from diseases. Do not just toss away the turtle in the trash can. Instead, follow a proper burial. After all, it was your favorite pet.

I know you can not think too much as you will process the death of your pet. So, I have got you covered. Check this article to explore your options with a dead turtle in hand.

4. Go & Arrange A Separate Feedings

Turtles chew food differently, which explains the food scraps. So, no matter where I feed these cuties, they will leave behind crumbs to rot and stink.

So, I have made arrangements to feed them in a temporary habitat.

The setup is nothing but a large plastic container with a few rocks. I fill the bowl, place the turtles inside, and toss the food inside.

This way, my pets enjoy their meals to the fullest, and I avoid unnecessary putrid odor in the tank. Yes, turtles will be a bit scared when you introduce them to the temporary feeding spot. They are shy and overprotective, after all.

Give the pets some space and allow them to spend time there. Soon, your turtles will adjust to this new meal setup.

If you are not so sure about this temporary setup, use nets to remove food scraps. But remember, the crumbs are small, and nets may not trap them all. Hence, you will be stuck with the rotten egg odor.

See also  How To Know If Your Turtle Is Happy? [7 Easy Signs]

5. The Bigger The Merrier

The more, the merrier. In turtle keeping, we say the bigger the merrier, meaning more space will only make your pets happier.

I have already talked about how disturbed turtles get when you overcrowd their habitat. They are very concerned about their territory and are not ready to share it with another turtle, let alone a fish.

But don’t just take turtles as unfriendly and rude. They will welcome the tank mates cordially only when there is enough space available. Of course, this can go otherwise, and these pets can be at each other’s throats. Trying to predict a turtle’s behavior is a foolish act.

However, providing turtles with bigger space has multiple advantages,

  • There will be fewer fights.
  • You can add more plants and fish, too (large and agile ones).
  • Most importantly, there will be less filth. So there is no unpleasant odor to handle.

6. Cleaning Is No Joke

Irregular tank cleaning is another reason our turtle tank can stink like a rotten egg. Luckily, that was not the case with my setup. I follow the ideal cleaning rule.

It means I not only change the water but also give the habitat a deep clean on a regular basis.

The target is to siphon 25 – 30% of the existing water weekly and replace the vacuum with fresh water. Besides, a thorough cleaning once a month is mandatory.

The cleaning steps will be,

  • Transfer the turtles to a temporary habitat.
  • Drain the aquarium water.
  • Remove the decorations and rinse them with water.
  • Scrub the tank bottom and walls.
  • Rinse the setup thoroughly and assemble everything.
  • Refill the tank.
  • Pour a few drops of conditioner.
  • Leave the habitat intact for hours.
  • Now, the enclosure is ready for the turtles again.

If your turtle enclosure includes a substrate, change the bedding too. The soil or gravel can trap food or pool, and the wastes eventually rot there, spreading a putrid smell.

Furthermore, use green solutions instead of commercial detergents and soaps. The commercial ones contain harsh chemicals that irritate the turtle’s skin and eyes. Using the turtle tank cleaners is also a good idea.

7. Everything On the Filtration System

Just as I said, turtle tank filters are of great significance. You will regret not buying the right size and quality for the pet’s habitat. Usually, the modern filters 1.5 to 2x the aquarium capacity is recommended.

The latest technology purifies and sterilizes the water in 3 stages. In the mechanical basket, the debris is removed. Similarly, the chemical media restores the ideal chemical balance, killing germs. Finally, the biological basket eliminates the nasty odor and promotes good bacterial growth.

Furthermore, make sure your filter settings are right and the device is working. Do not forget to detach the media baskets and clean them thoroughly once a month. Change the bio balls or filtration pads if necessary.

Before You Go…

Well, we can barely withstand the stomach-sickening odor coming from the habitat. Right? But what about turtles? Can they smell? Get an insight into the turtle’s olfactory response from the attached article.

Can Turtles Smell Underwater?

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About Author

Muntaseer Rahman started keeping pet turtles back in 2013. He also owns the largest Turtle & Tortoise Facebook community in Bangladesh. These days he is mostly active on Facebook.


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