Goldfish Sitting on Bottom of Tank? (Treatments and Causes)

Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: February 23, 2024
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It can be alarming for any aquarium enthusiast to spot a goldfish resting at the bottom of the tank. Occasionally, it could be a harmless sight of a healthy goldfish taking a nap or a break, but it could potentially indicate a more serious issue. If you’ve observed this behavior in your goldfish aquarium, continue reading to gain deeper insight into what it might imply for you and your pet fish!

Article Summary

  • Goldfish sitting at the bottom of the tank can be a normal behavior, especially during sleep, but it can also indicate potential issues.
  • Stress is a common cause of goldfish sitting on the bottom, and it can result from changes in the tank environment or other factors.
  • It’s important to differentiate between a sick fish and a sleeping fish, as goldfish do sleep and may sit at the bottom during rest.

Is It Normal For My Goldfish To Sit On the Bottom of the Tank?

While not usually a regular goldfish behavior, sitting on the bottom doesn’t mean something is necessarily wrong!

Consider conditions in your tank, and how your fish normally acts before jumping to any major conclusions regarding health.

Why Is My Goldfish Sitting on the Bottom of the Tank?

Stress

It may seem unusual to think of something like stress being an issue for something that appears as calm as a typical fancy goldfish.

However, goldfish and many other fish are in fact quite sensitive to overstimulation. While harmless at first, continued exposure can lead to illness and even death.

One of the most common reasons to see any difference in the behavior of your goldfish is stress.

Causes

Goldfish Near Substrate
Goldfish Near Substrate

This may be caused by a variety of changes to the tank, such as the introduction of new tank inhabitants, water stress from changing conditions, shock from extra light, to being a recent new fish from the pet store themselves.

NOTE
Signs of stress include seeing a lethargic fish, sitting at the bottom, and in some cases unusual behavior such as swimming sideways, clamped fins sitting against their body, or moving towards the surface.

Prevention

The key thing to keep in mind with stress is that it can be prevented.

Careful handling of your goldfish, along with close attention to the water condition, nutrition, and amount of stimulus your fish is exposed to goes a long way towards keeping your fish happy and healthy.

Things to change

If you notice that a particular fish is stressed out, there are a few helpful things you can do.

Lowering the lights, removing any additional sources of loud noises, and potentially even moving the goldfish to its own small bowl can see a change in as little as a few hours to a few days, depending on severity.

Environment

Environmental factors play a huge role in the growth and health of the goldfish.

Things like tank size, lighting, plants, even substrate gravel all play a part in your goldfish’s own aquatic world and can determine how they feel and behave.

Too small of a tank or fish bowl can lead to your goldfish staying fairly stationary.

RECOMMENDATION

We recommend a minimum of at least 20 gallons for one goldfish, with 5-10 gallons per additional fish after that.

Tank Size

Fish Tank
Setting up an Aquarium

Although a goldfish can live in a bowl, a small space means that the goldfish will never truly feel comfortable or like they have enough room, which may mean they sit at the bottom.

In general, there is no such thing as too much swim space for a goldfish! When in doubt, choosing a bigger tank over a small one will lead to a happy healthy fish.

Regular cycles of lighting are critical to goldfish health.

Like many other fish they require a consistent night and day in order to fall asleep, and moving away from this can make them stressed.

TIP

Using an aquarium timer is a great way to create a consistent sleep cycle for your goldfish while taking the pressure off of your to monitor this task yourself. 

Plants

Goldfish in a Planted Tank
Goldfish in a Planted Tank

Live aquarium plants are a great way to introduce oxygen to the tank, control nitrogen levels, and give your goldfish something else to interact with. Goldfish love to explore plants, using them to hide in instances where they may feel threatened or have the need to make their own swim space.

While goldfish can tolerate algae to a certain degree, if you start seeing the presence of excess plant material floating around your tank it’s usually a sign of poor water quality.

Look into increasing the filtration present in your tank, and consider a regular water change.

If you don’t want more plants in your tank. Another way to increase the dissolved oxygen in your tank is through surface agitation. Try installing an air stone/bubbler, or air pump in your tank.

Water Parameters

Testing the quality of your water on a regular basis, monitoring temperature, and keeping an eye on the presence of excess sediment buildup are key components of preventing sick goldfish on the bottom of the tank.

Seeing floating bits of debris and algae filled water is a bad sign!

Such conditions can end up causing disease to your goldfish, along with the high likelihood that there isn’t enough oxygen in the tank.

NOTE

Most pet stores sell testing kits that can help you look at factors such as pH, salinity, and ammonia levels.

Water Quality

Goldfish Swimming in a Tank
Goldfish Swimming in a Tank

Goldfish naturally produce quite a bit of waste, which greatly affects the water quality.

More goldfish and other fish means more waste, which can rapidly spiral to unhealthy levels if your filtration system isn’t up to the task.

Make sure that you know the amount of filtration that you need for your goldfish aquarium and number of fish.

While the biological filter created by the beneficial bacteria in your tank can help, pumps and filters will be needed to move larger debris out of the tank.

Water Temperature

As a fairly hardy fish, goldfish can handle a range of temperatures outside their preferred range of 60-70 degrees.

While 10 degrees above or below this range will not likely cause much harm, a rapid or larger shift in temperature can lead to temperature shock. You can use a heater when creating a goldfish tank to help make the temperature consistent or if its too cold.

Temperature Shock

A shocked fish will show many of the same distress signals as a stressed one, and may begin the process of partial hibernation if too cold, becoming lethargic and sitting on the bottom of the tank.

NOTE

Too high of a water temperature can at first lead to a flurry of activity as the fish readies to swim extra for breeding season. After time, the fish will tire, leading to goldfish laying on the bottom of the tank.

Ammonia Levels

Goldfish Feeding
Goldfish Feeding

Excess waste, decaying once-live food, and the presence of dead goldfish and plants can all raise the ammonia level in the tank.

High ammonia levels can be dangerous because it can damage the cells and tissues of goldfish.

With high ammonia levels, you’ll see your fish with clamped fins, goldfish hanging motionless and unable to move, black coloration, and potentially inflamed or reddened as their tissues continue to break down.

Maintaining Ammonia Levels

In a normal healthy circumstance, you should see ammonia levels of no more than 2 parts per million.

Ideally, you should be able to keep that level to zero with weekly regular water changes, along with continued monitoring for poor water quality.

TIP
To prevent high nitrate levels, monitor your tank when feeding, especially with new foods. If after 30 minutes the food remains uneaten, remove it before it has the chance to begin releasing ammonia.

Diseases

Sick Goldfish At The Bottom of the Tank
Sick Goldfish At The Bottom of the Tank

A newly sick goldfish will begin displaying signs of illness by appearing lethargic and sitting on the bottom of the tank.

Some fish may simply hang in one place, unable to control their buoyancy properly as bacteria damage their air bladders.

If you suspect a goldfish of illness, remove the affected fish to a separate hospital tank for treatment in order to prevent spread.

Parasites

Parasites are most commonly introduced when fish are brought into a tank without proper acclimation time.

Fish straight from the pet store can carry all kinds of disease and organisms on-board, which will jump from the new fish to your goldfish.

Goldfish affected by parasites will often swim irregularly, and may show inflammation or different colors in the area in which the parasite lives.

Parasites can commonly be remedied with the use of medications which can be found and your local pet store or veterinary clinic. A parasite that commonly affects goldfish is ich.

Constipation

Goldfish Swimming
Goldfish Swimming

If your goldfish was overfed or has recently eaten something hard to digest, such as bread or fibrous veggies, its body will struggle.

The fish will likely not eat and sit on the bottom of the tank, unable to pass these foods through their system. Along with the issues related to constipation, unhealthy foods can mean poor nutrition overall which will lead to a sick, unhealthy fish.

Swim Bladder Issues

The swim bladder is the air filled organ in a goldfish that allows for movement throughout the tank.

When your fish gets swim bladder disease, this air becomes either too concentrated or may dissipate, leading it to either sit on the bottom of the tank, float awkwardly around, or swim sideways in the tank.

Here’s an informative video about swim bladder disease

SWIM BLADDER DISORDER – How to Treat and Prevent it

Treatment

To resolve swim bladder disease, consult your veterinarian or local pet shop as to which medication is right for your fish.

A good first step is to move the sick fish to a quiet, isolated tank so that it is not further stressed and can’t introduce illness to your other fancy goldfish.

Eggs

Goldfish keeping can come with the added bonus of additional baby fish if you attempt to breed.

The problem for some females comes when they become egg bound, which can be an uncomfortable situation where they swim with great difficulty or not at all.

This should pass once the goldfish is able to properly lay eggs, but if you don’t see them swim normally within a day or two after laying it may be a sign that something else is wrong and that they should be closely monitored for other symptoms of infection or disease.

Bored

Goldfish in an Aquarium
Goldfish in an Aquarium

Unlike humans, you will never see a bored goldfish.

They are not naturally social animals and do not need companionship or much activity to remain stimulated, although it can be nice to place small toys throughout to make things more interesting for you.

Fish feel hunger, pain, and tiredness; that’s a fact, but they will likely not be made happier by aquarium toys.

TIP

If looking for an alternative to lots of little aquarium toys all over the place, consider adding some plants and decorations for your curious fish to explore.

Sleeping

Do goldfish sleep? Definitely yes! And in most instances, the fish sitting at the bottom of the tank is simply a sleeping goldfish!

Goldfish sleep 8-12 hours per night, and if for some reason they are unable to get regular darkness during their day they may need to nap to catch up on the proper amount.

Check for Signs of Life

Goldfish at a Corner of a Fish Tank
Goldfish at a Corner of a Tank

To check whether you have a sick fish or one that is sleeping, it is ok to gently move some water towards them in the tank.

If they react and wake up, they are likely just sleeping.

If they continue to remain still, you may have a sick pet on your hands and need to take more drastic measures.

Death

The unfortunate fact is that some fish sitting still on the bottom of the tank may in fact be dead. Look for typical signs of life such as gill and fin movement, heartbeat, and eye movement, and try to notice any foul smells in the tank.

Most dead fish will float to the surface if slightly jostled, as the gas expanding inside is more buoyant.

While a sad moment in any aquarist’s life, the dead fish should be removed as soon as possible to prevent ammonia releasing as it decays and potential spread of disease if that’s what caused your goldfish to die.

Conclusion

Throughout today’s article, we’ve looked at several of the different causes for why your goldfish may be sitting on the bottom of the tank.

From simple-to-fix things like simply having a sleeping fish or a stressed out one, to more serious issues such as disease and poor water quality, the main takeaway is to keep a close eye on your fish and the tank itself so that you can respond early to any changes.

Feel Free To Share!

As always, we hope that you’ve found today’s article informative and that it helps you along your aquarium adventures!

Please feel free to share with any other fish fanatics in your life, and we wish you the best of luck out there.

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