Betta Fish Laying On Bottom Of Tank -12 Reasons Why (And How To Fix It!)

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Betta Fish laying on bottom of tanks can be one of the scariest things a new betta keeper can experience. After all, it’s usually a telltale sign something is wrong with your fish. That’s not always the case with Betta fish though. There could be multiple reasons why (some good and some bad). Today’s articles talked about the reasons and how to fix the issue if it’s for a bad reason.

Let’s dive in!

Introduction To Betta Keeping

No matter what kind of fish you have, you never want to see it laying on its side at the bottom of the tank. This behavior is usually a telltale sign that something is wrong in the aquarium whether it be illness and disease, poor water quality, or stressful tank mates. Prolonged laying on the substrate can eventually cause secondary infections to form due to new scrapes and scratches as well as torn fins; betta fish especially are prone to developing fin rot.

Unfortunately, seeing a betta laying on the bottom of a tank is a common sight in commercial pet stores. This can fool beginner hobbyists into thinking that it’s the natural behavior of their fish when they bring it home. This, in addition to the general misinformation surrounding betta fish, leads to many unnecessary fish deaths.

This is not normal betta fish behavior and your betta fish should never be laying on the bottom of the aquarium. But how can you make sure to keep your betta fish happy and healthy?

Tank Size

It’s a common misconception that betta fish don’t need a lot of space. While this is mostly true, they definitely flourish when given the space to thrive.

Betta fish are commonly kept in 1-gallon betta tanks that haven’t undergone the nitrogen cycle. Sadly, beginner hobbyists are often left wondering what happened to their fish. In general, betta fish need at least a 5 gallon, fully-cycled, and heated aquarium.

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From there, hobbyists may add live plants and appropriate tank mates while keeping up water quality and keeping the betta enriched. Of course, hobbyists have been successful in keeping these beautiful fish in smaller setups, but this is only recommended for more experienced betta keepers.

Water Parameters

In addition to an appropriately sized tank, betta fish also need a fully-cycled and heated aquarium. Many times, these fish are thrown into an uncycled tank where they are left to succumb to ammonia poisoning or another water quality problem. With some patience, keeping water parameters right for betta fish is easy.

Betta fish need 0 ppm ammonia, 0 ppm nitrite, and minimal nitrate at all times. As we’ll see, excess levels of these parameters can quickly cause the betta’s health to deteriorate, which can lead to death in some cases.

Betta fish originate from very acidic conditions in Southeast Asia with pH levels under 7.0. Many of the fish available at local pet stores today have been bred in the aquarium industry and have adapted to a relatively neutral pH between 6.0-8.0, though stability is key.

These fish are also a tropical species and need an aquarium heater to keep the water temperature between 78-80° F. Too many hobbyists try keeping these hardy fish at ambient room temperature and find themselves with a stressed-out betta due to fluctuating water temperatures.

Tank Mates

Yes, it’s possible to keep other fish with your betta fish. However, this will largely depend on the personality of the individual fish.

Some betta fish might not tolerate other fish or invertebrates in their aquarium at all. Others may accept some but not others. And then there are those few lucky hobbyists that have a betta fish that accepts any and all new tank additions, though betta fish may also change their mind at any given moment.

Still, there are several tried and true species that have made perfect betta fish tank mates. These include:

If keeping female betta fish, it may also be possible to start a betta fish sorority tank, though this setup is usually considered more advanced.

Betta Fish Laying On Bottom Of Tank (12 Reasons Why)

Betta at bottom of tank

There is only one instance when it is normal for your betta fish to be laying on the ground and that is when it is sleeping. Otherwise, there is probably a problem with tank or water quality or you’re dealing with an illness.

Here’s how to identify the problem and what to do to get your betta fish feeling better.

1. Sleeping Betta Fish

Yes! Fish sleep. Though it’s not in the same way other animals do.

Instead, fish will have brief sleep cycles where they enter the REM stage throughout the night1. This can make for some interesting behavior in an animal that doesn’t have the ability to lay down. Many new hobbyists might worry that their betta is sick due to abnormal behavior once the lights go out, but usually, it’s just your betta trying to get some shut-eye.

Here’s how to tell that your fish is sleeping.

Usually, fish have a preferred spot to rest once the lights turn off. In a planted aquarium, this might mean a favorite leaf or spot behind a decoration. They will then lightly float near the object, sometimes in weird orientations. It might even appear like they stop swimming altogether and almost slip off the item.

Other bettas might enjoy laying on the substrate. This is simply a preference, but it can definitely be concerning when you see your fish at the bottom of the tank starting to fall sideways.

If this happens every night, it’s normal. Fish are weird sleepers. However, if this starts happening during the day or you notice abrasions or ripped fins starting to form, then this can become a more serious issue.

2. Older Betta Fish

Just like you and me, betta fish get weaker as they age.

They might not be able to swim in a straight line from the top of the aquarium to the bottom of the tank, and might find themselves resting on a leaf or aquarium equipment. If your betta fish is especially exhausted, it may even take a quick break at the bottom of the tank.

Unfortunately, all bettas age. Continue to monitor your fish for cuts and scrapes and give your fish the best days possible!

3. Ammonia Poisoning

If your betta fish isn’t sleeping and isn’t old, then there is more than likely something wrong with the tank or with water conditions. One of the leading causes of betta fish laying on the bottom of the tank is ammonia poisoning.

Ammonia is a natural compound in the aquarium; fish and invertebrates constantly create waste that is then processed by beneficial bacteria populations. The highest that ammonia levels should ever go is when the tank is cycling. It should remain close to 0.0 ppm at all other times.

But what happens if you add too many fish or you accidentally feed too much at one time? You may experience a mini-cycle where ammonia levels increase, causing an imbalance in bacteria populations.

Unfortunately, ammonia is a deadly chemical. Any significant amount of ammonia in the aquarium will cause injury to the external and internal organs of fish and invertebrates. Eventually, their gills are burned and they are unable to breathe.

This side effect can lead your fish to gasp for air at the bottom of the tank. At this stage, it’s pretty late for your fish. However, water changes, water conditioners, and ammonia-reducing filter media may help bring down the ammonia levels just in time.

4. Nitrate Poisoning

If you experience a mini-cycle, then it’s likely you’ll get a large influx of nitrates as well.

When ammonia enters the aquarium water, it is converted from ammonia, into nitrite, and finally into nitrate. Unlike the others, nitrates can only be quickly removed from the aquarium with a water change. This is why it’s recommended to do a near-100% water change after a betta tank has finished cycling.

Luckily, nitrate poisoning only occurs when there are very high levels of nitrate in the aquarium water. By the time nitrates accumulate enough in the betta fish tank to cause nitrate poisoning, it’s likely that your betta fish will have died from a prior cause. However, nitrate poisoning is a real possibility after cycling the aquarium.

Nitrate poisoning will quickly lead to poor health in your betta. One of the more severe symptoms is if the betta fish lays on the bottom of the tank.

To make sure your betta fish never experiences nitrate poisoning, regularly perform water changes and test water parameters.

5. Swim Bladder Disorder

The swim bladder is responsible for regulating a fish’s buoyancy in the water column. Symptoms of a swim bladder disorder include difficulty maintaining an upright position, bloatedness, curved back, and sinking or floating to the top of the water.

Swim bladder problems aren’t entirely understood, though they’re believed to be a secondary symptom of a more major problem, like water quality or another illness. One of the ways betta might also be affected is by taking in too much oxygen while they eat food at the surface of the water.

The main treatments for swim bladder disorder are increasing water quality through water changes, changing diets, and possible medication.

6. Small Aquarium

Another reason you might find your betta fish laying on the bottom of the tank is due to a small aquarium. Betta fish are notorious for being kept in poor conditions due to being a beginner’s fish. Not only does an overly small aquarium stress out betta fish, but less water volume can lead to fluctuating water parameters.

Betta fish require a 5-gallon, fully-cycled aquarium; some hobbyists have success keeping these fish in smaller setups, but 5 gallons is usually the bare minimum recommended. This gives the fish enough space to freely swim while providing an interactive environment to keep your fish from getting bored.

A bigger aquarium also means that water parameters aren’t affected as quickly or as much should a problem arise in the system, which leads to a more healthy betta overall.

However, a small aquarium can lead to poor water quality and a bored betta left laying on the bottom of its tank.

7. Temperature

One of those affected water parameters could be water temperature.

Betta fish are very hardy fish in all regards but they’re a tropical fish that needs a constant water temperature between 78-80° F. Unfortunately, these fish are often kept in unheated aquariums with fluctuating temperatures due to misinformation surrounding correct betta care.

Betta fish always need an aquarium heater for temperature stability as incorrect or fluctuating water temperatures can cause the fish to go into shock. The inability of your betta fish to physiologically adjust to its environment can quickly lead to a lethargic and dying betta.

8. Wrong pH

Possibly even worse than a wrong water temperature is a wrong pH.

In the wild, betta fish live in slightly acidic water conditions due to tannins that enter the water column when organics start to break down. Since they’ve been bred in the freshwater aquarium for a long time, most betta fish are able to adapt to a more neutral pH, near 7.0. Most aquarium keepers keep their betta tank pH between 6.0-8.0.

The problem is that pH is measured on a logarithmic scale that makes differences in numbers an exponential change; what might seem like a slight change in pH is actually much greater than it might read.

That being said, it’s normal for aquariums to experience changes in pH throughout the day, especially in a well-planted tank where there are varying levels of photosynthesis and respiration. However, if pH changes more than 0.5 a day, this can become stressful and even deadly for the betta fish.

9. Filtration Issues

In addition to a heater, betta fish also usually require a filter that is properly sized for a betta tank. Finding a properly fitting betta fish filter can be difficult. It needs to be rated for at least 5 gallons but can’t be so strong that it pushes your fish across the tank.

This is a common problem for betta keepers: a good quality filter that has too much water flow. As a result, betta fish can be pushed around and injured and left struggling to recover at the bottom of the tank.

Filters that don’t provide enough surface area for adequate beneficial bacteria populations to grow can also lead to poor water quality which can greatly affect bettas.

The solution to both these problems is using an aquarium filter that can keep up with the bioload of the system by modifying or baffling the water flow. Some hobbyists even turn to a sponge filter instead of a hang on the back system so that flow isn’t as overwhelming.

10. Poor Diet

In the wild, betta fish have a wide assortment of plants, algae, insects, and detritus to choose from to eat. While this can surely be replicated in the aquarium setting, a high-quality fish flake or pellet can usually meet the nutritional needs that bettas need to thrive.

However, a low-quality food, or one that is meant for other species, may not fulfill all the vitamins and nutrients your fish requires to perform regular tasks, such as swimming. Irregular feedings and lack of feeding can also cause fish to become weak and malnourished.

Many low-quality betta fish foods have fillers in them that add no nutritional value. This can lead to indigestion problems, such as constipation.

11. Lack of Interaction

Betta Fish Interacting with Reflection

As mentioned before, bettas can become bored in their environments, especially in a very small tank where there isn’t much to do.

Though betta fish are solitary fish, they require enrichment. A bored betta may sink to the bottom of the tank, waiting for something new to enter its home.

Even though fish aren’t the most intelligent animals, they still appreciate being visited by their owners every day. They will develop a routine and schedule around when hobbyists feed the tank or perform tank maintenance; just watch how your betta fish reacts the next time you go near its tank!

Betta fish do not need to be constantly entertained and small additions, like invertebrate tank mates, live feedings, or the addition of live plants, can give your betta fish just enough change in their environment so they don’t become bored.

12. Poor Tank Mates

At the same time, you don’t want to add tank mates that will cause your fish to become stressed out from being overactive. Larger, aggressive fish may even chase your betta and exhaust it, leading them to get injured and lay on the substrate.

There are plenty of betta fish tank mate options that have proven to be successful, but many pairings are not; success will also greatly depend on the personality and behavior of the individual betta fish as not all may be as welcoming as other fish.

Final Thoughts

Betta fish are very hardy fish, but unfortunately, a sick betta fish can succumb to a variety of water parameter problems and illnesses relatively fast. If you find your betta fish laying at the bottom of the tank then check water parameters immediately and check for signs of disease.

If there are no signs of a problem with either, then your fish might just be sleeping or getting older!

by Mark

Mark is the founder of Aquarium Store Depot. He started in the aquarium hobby at the age of 11 and along the way worked at local fish stores. He has kept freshwater tanks, ponds, and reef tanks for over 25 years. His site was created to share his knowledge and unique teaching style on a larger scale. He has worked on making aquarium and pond keeping approachable. Mark has been featured in two books about aquarium keeping - both best sellers on Amazon. Each year, he continues to help his readers and clients with knowledge, professional builds, and troubleshooting.

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