Why is Goldfish Not Swimming?

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Goldfish are some of the most popular tank fish for several reasons, including their diversity, hardiness, and friendly demeanor.

But, despite their resilient nature, they can sometimes struggle in poorly maintained habitats and inadequate aquarium conditions.

Depending on what’s affecting them, goldfish will display an array of symptoms, one of which has to do with their swimming pattern.

If your goldfish is not swimming, swimming to the water surface too frequently, or remaining near the substrate for too long, something’s not right.

And, if you know anything about fish diseases, you know that early diagnosis and treatment are vital. Most fish disorders are both contagious and deadly when left unchecked.

Today, we will look into the goldfish’s odd behavior under certain circumstances to see what it means.

Reasons Goldfish Not Swimming

Goldfish aren’t exactly the most active fish in the world, but they aren’t sluggish either. Their typical behavior involves patrolling their environment, interacting with other fish, and checking their habitat at a comfortable pace.

While they sometimes take a short rest near the substrate or plants, it’s unusual to see them refusing to swim for prolonged periods of time. Except if it’s nighttime and they’re in for some short naps.

Other than that, if your goldfish refuses to swim, consider the following problems:

  • Stressed Goldfish
  • All fish will display stress under specific situations, such as:
  • Poor water conditions, causing goldfish visible discomfort
  • Aggressive tankmates that bully, poke, or attack them relentlessly
  • Parasitic or bacterial infections causing pain or itching
  • Improper diets that cause digestive problems like constipation
  • Sudden or aggressive changes in water parameters, like temperature fluctuations and drastic pH shifts
  • Overall discomfort due to various diseases

This goes to show that identifying the cause of their stress is essential. In many cases, their stressed behavior is indicative of other, more serious underlying conditions that need addressing fast.

Ignoring your goldfish’s signs of stress can quickly devolve into more serious problems, primarily because of how extended stress affects the fish.

Goldfish living in conditions of stress experience weaker immune systems and are always more vulnerable to diseases and parasites.

This is a key point to focus on since many tank fish already have a variety of parasites in their intestinal tract, including those responsible for conditions like Ich, dropsy, and swim bladder disease.

The problem is that they’re not active since the fish’s immune system keeps them in check, preventing them from reproducing.

A stressed fish won’t have its immune system by its side. This will allow the parasites to take over, multiply, and infect the whole tank, killing their hosts in the process.

As you can see, fish stress is not a benign issue.

Poor Water Quality

Goldfish require stable water parameters to thrive. Drastic changes in their water parameters will cause numerous health problems, most of which begin with subtle behavioral changes.

If your goldfish appears less active than it used to be, consider the following:

  • Water temperature is too low – Goldfish like colder waters, in the neighborhood of 68 to 74 F. The problem with the water temperature dropping too low is that it lowers the goldfish’s metabolism, depleting its energy and forcing it to enter a lethargic state. The fish does so to preserve its energy due to its lower metabolic rates. The goldfish won’t mind temperatures below its comfort threshold for some time, but not all the time. After a while, your goldfish may begin to experience signs of stress, and we’ve already discussed where that leads. In more extreme cases, the goldfish may even experience temperature shock, which can be deadly.
  • The water is too dirty – There are a lot of factors contributing to this problem. Some of them include overfeeding, lack of water changes, lack of tank maintenance, overcrowding, algae bloom, bottom-feeders causing a mess, etc. The real problem here is that goldfish are extremely messy fish. Probably the messiest you can find. On the one hand, they poop a lot due to lacking a stomach, allowing the food to traverse the digestive system faster. On the other hand, they dig into the substrate to look for food, projecting all of the food residues and fish waste into the water. This is why goldfish require more strict maintenance work than other fish.
  • Dangerous water chemistry – This is the result of 3 primary triggers: lack of tank maintenance, overfeeding, and lack of water changes. All these 3 problems combined will lead to one verified outcome – the dangerous accumulation of ammonia and nitrites. A perfectly balanced aquatic environment contains a lot of nitrifying bacteria whose main role is to convert ammonia and nitrites into nitrates. The problem is that not cleaning the tank, overfeeding your goldfish, and skipping your weekly water changes will quickly overwhelm these microorganisms. This is especially true when considering that we’re talking about goldfish, which rank as champions at poop production. As a result, ammonia levels will increase dramatically, altering the water’s chemistry with potentially fatal consequences.

So, how do you fix this problem? I have several solutions for you that you should consider as a whole, taken together:

  • Regular tank maintenance – I’m referring to vacuuming the substrate and removing algae overgrowth as the main activity. How often you should do that depends on how many fish you have, how large the tank is, and how fast it gets visibly dirty.
  • Weekly water changes – Yes, goldfish require partial water changes every week, typically consisting of 10-15% of the total water volume. You may have to perform more frequent water changes if you have a crowded tank with a thriving goldfish population.
  • Avoid overfeeding – This is one of the primary causes of ammonia boosts in any fish tank. It’s even more dangerous with goldfish, knowing their abilities to produce impressive quantities of poop. Feed your adult goldfish twice per day at most and provide sufficient food for them to consume within 3-4 minutes.
  • Consider a more well-rounded filtering system – This is especially a must in larger tanks, holding a lot of fish. You need a filtering system to provide mechanical, biological, and chemical filtration and is capable of filtering a water volume equal to 5-10 times the tank’s capacity. For larger tanks, you might require either a very powerful filter or 2 filters set on opposite ends.

Naturally, you should adapt these methods to your situation, depending on your tank’s size, how many fish you have, how big the fish are, etc.

But you should stick to a healthy maintenance routine no matter what.

Aggressive Tank Mates

Goldfish are friendly aquatic creatures that prefer the company of like-minded fish. Pairing goldfish with species like tiger barbs or various species of cichlids is set to spell disaster soon.

The more aggressive fish take the voluminous and friendly goldfish for target practice. They will poke at them, nip at their fins, and force them into hiding, which will eventually affect the goldfish’s mental health.

To avoid that, I suggest avoiding aggressive tank mates. It’s the easiest and most obvious solution. Don’t pair your goldfish with territorial, aggressive, or even overly inquisitive fish.

Instead, go for species like danios, Corydoras, loaches, and other fish that match goldfish in terms of water requirements and personalities.

You should also observe how the goldfish react towards one another. Male goldfish won’t become the best friends in the world. They will often display territorial behavior and become competitive over food, hierarchy, and females.

In this case, providing your fish with plants and various decorations to break the line of sight between bullies and the bullied can mitigate the violence.

If the aggressors don’t cool off, you might want to remove them from the environment, especially if they’ve had a lot of recent episodes of violence.

Disease or Parasite

Goldfish can’t complain when dealing with diseases or parasites, so they will display their discomfort via other means. One of them is the refusal to swim and remaining close to the substrate for longer periods.

At this point, you should begin looking for additional symptoms, such as:

  • Low or non-existent food appetite
  • Signs of aggression towards other tank inhabitants
  • Lethargy and overall low energy when swimming
  • Bumping and rubbing against hard surfaces may indicate some skin parasites
  • Any alarming changes in coloring or discoloration on some body areas
  • Cotton-like growths around the eyes or mouth
  • White and stringy feces
  • Visible bloating or even sunken bellies, etc.

These symptoms aren’t specific to one condition but multiple. So, additional tests are necessary to determine your goldfish’s health problem.

Whatever the case may be, you should consider the following approaches:

  • Quarantine – The first and most important step. You should always quarantine your goldfish if you observe any abnormal behavior or any of the signs I’ve mentioned. Parasites like Ich, for instance, are extremely aggressive and can contaminate the entire tank fast. In that situation, quarantine is necessary to disrupt the parasite’s life cycle, provide the sick fish with targeted care, and protect the other fish from infection.
  • Ensure premium care – Perform daily partial water changes, remove fish waste and food leftovers immediately, and keep the tank water crystal clear at optimal parameters. Such an environment will boost the goldfish’s recovery rates, allowing them to heal faster.
  • Use adequate medication – Antibiotics are a must to address viral infections involving external pathogens. You may need to use specific medication for internal parasites, depending on your vet’s recommendations.

You should also provide a balanced and nutritious body to help the goldfish fight off the disease.

As a plus, monitor your goldfish’s progress during treatment to determine when it has managed to overcome the problem.

Ammonia Poisoning

This deadly problem is more prevalent among novice aquarists, skipping too many tank maintenance sessions. Ammonia is the natural byproduct of dead organic matter decaying in the tank’s water.

This includes unconsumed fish food burying itself in the substrate, fish poop, dead plant matter, and even dead fish not being removed quickly from the tank.

Your tank has a natural biofilm consisting of billions of nitrifying bacteria consuming ammonia and converting it into nitrites and then nitrates.

The latter isn’t as damaging, so your goldfish can tolerate them at average values between 8 to 20 ppm. However, the problem is far more severe when it comes to ammonia.

Any value past 0 will affect your goldfish’s health and is capable of inducing ammonia shock and symptoms of ammonia poisoning.

Some of these symptoms include:

  • Hiding behavior and reduced swimming activity
  • Gasping for air at the water’s surface as ammonia burns the fish’s gills, causing suffocation
  • Rapid gill and mouth movement
  • Decreased appetite
  • Excessive mucus production as the body attempts to protect itself from the chemical
  • Red lesions on the skin
  • Inflamed, red, or even bloody gills

These are worrying symptoms, warning of the possibility of ammonia poisoning. In case of extreme levels of ammonia, your goldfish will experience coma and even sudden death.

And the problem is that ammonia can kill fish fast.

The treatment should come in early and consists of quarantining the fish in a clean and balanced environment with optimal water conditions.

Provide the fish with a balanced diet and use medication to treat any secondary infections if necessary. But, ultimately, the most effective ‘treatment’ comes in the form of prevention.

Your goal should be to prevent any ammonia formation in the tank, which requires you to:

  • Avoid overfeeding – Goldfish can easily eat more than they need to. Limit their meals to 2 per day and only offer sufficient food for them to consume in 4 minutes tops. Also, remove any leftovers if necessary. It may seem like a chore, but this will minimize the need for too frequent tank maintenance.
  • Manage the pH values – Few people are aware of the pH’s influence on the ammonia levels in the tank. Goldfish require pH values around 7.0 to 8.0 to remain comfortable and healthy. Anything below 6.0 will not only hurt goldfish directly but indirectly as well since the Nitrosomonas bacteria cannot process ammonia if the pH level drops below that. You can see the problem here.
  • Embrace a robust tank maintenance routine – Keep the tank clean, perform your weekly partial water changes, and constantly monitor your fish’s environment. You should immediately address any worrying fluctuation in the water parameters to prevent drastic changes in the water’s chemistry.

And don’t forget the bit about goldfish being an extremely messy fish that I’ve already mentioned.

Why is Goldfish Laying on the Bottom of the Tank?

There are several reasons for that, most of which we have already mentioned.

To summarize:

  • Stress caused by aggressive tank mates or poor water conditions
  • Parasites, bacterial infections, or diseases that cause significant physical discomfort
  • Physical injuries, either accidental or intentional, resulting from fighting other tank mates
  • Ammonia or nitrite poisoning

If you’ve eliminated all these problems off of the list, there are 2 more you might want to consider:

  1. Sleeping – Goldfish tend to sleep mostly at night, but they will also take occasional naps during the day. Many will rest near the substrate, so this isn’t a worrying behavior. It may become worrying depending on the fish’s body positioning. Goldfish tend to tip their heads downwards slightly when resting but will never go completely upside down. They will also avoid tipping on their sides. These are worrying signs that something’s not right with them.
  2. Gravid fish – Female goldfish will rest near the substrate when the time comes to lay the eggs. The female will also spend a lot of time near the substrate when stressed by other fish, particularly males fighting over the honor to fertilize its eggs. This is also normal behavior.

Why is Goldfish Swimming at the Surface?

If your goldfish appears to spend a lot of time near the water’s surface, there’s only one explanation for that – poorly oxygenated waters.

All fish breathe dissolved oxygen that hasn’t formed the H2O molecule yet, and the tank holds more dissolved oxygen at the surface.

The issue is that, in a healthy aquatic environment and under optimal environmental conditions, the water should have dissolved oxygen deeper as well.

If that doesn’t happen, there’s only one possible explanation – the water is poorly oxygenated.

There are several reasons for that, including:

  • Overcrowding – Having too many fish competing for the same oxygen is never a good idea. Overcrowded goldfish will struggle to breathe, causing them to exhibit rapid gill movement and swim near the water’s surface.
  • Poor water conditions – The dirtier the tank water is, the more difficult for fish to breathe properly.
  • Higher than normal temperatures – The warmer the tank water is, the less the amount of oxygen it can hold. Always monitor the water’s temperature to prevent that.
  • Inadequate aeration – Goldfish don’t like stagnant waters. Provide them with a moderate water flow and proper aeration to prevent breathing issues.

All these problems can be fixed via an adequate filtering system, providing aeration and keeping the water clean and fresh.

Why is Goldfish Hiding and Not Swimming?

This is a sign of fish stress more often than not. As we’ve already discussed, goldfish can experience stress for a variety of reasons, including poor water quality, improper tank mates, ammonia, or poor oxygenation.

Female goldfish will also hide from males when gravid and ready to lay their eggs.

To differentiate between normal and abnormal behaviors, I suggest assessing your fish’s behavior more in-depth to look for additional symptoms.

You will then take appropriate measures to fix the situation before aggravating it, which usually involves quarantining the fish in the process.

Is My Goldfish Sleeping or Dying?

This is a common issue among novice aquarists with little experience in goldfish or even fish in general. Fortunately, I have an easy fix for you.

When it comes to differentiating between dying or dead fish and sleeping ones, you should consider:

  • Signs of breathing – This is the first thing to check. Verify the fish’s vital signs visually to see whether its gills and mouth are moving. If they move at a constant rate, the fish is most likely just asleep. You should also look for slow fin movements as the fish will move them even when sleeping to maintain its position in space. The latter brings us to the next point.
  • Body position – Goldfish will sleep at an angle, slightly tipping their heads down. However, they won’t tip upside down completely, nor will they float or lay on their side on the substrate. The latter is a sign of parasites, bacteria, digestive problems, or anything along these lines. That is unless the fish is already dead.
  • Verify the eyes – A healthy fish’s eyes are clear and vivid. So, if your goldfish is either dead or dying, its eyes will become cloudy and sunken.

If you’re unsure what to make of your fish’s state despite these indicators, place your hand in the water and give the fish a couple of nudges. If it doesn’t react to the stimuli, your fish may have already died.

At this point, it’s imperative to remove the body from the tank to prevent the dangerous formation of ammonia and other chemicals that could poison the water.


Goldfish are active but laid-back fish that will roam around their environment at a steady rate. A healthy goldfish should remain active and only rest for short periods.

If your goldfish appears inactive for prolonged periods, monitor its behavior to detect anything abnormal.

This allows you to diagnose any potential health issue in its early phases and increase the treatment’s success as a result.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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