Have you ever wondered why fish just stay in one spot? My fish would just sit in one spot for hours at a time, and I had no idea why. So, I was curious and researched why it would be doing that.
What it means when fish stay in one spot:
- They are sitting in a warmer spot of the tank.
- They are sitting in a colder spot of the tank.
- They are sleeping.
- They have a reason for being in a certain part of the tank.
- They are hiding.
- They are stressed.
There are a lot of reasons why a fish may be staying in one spot of their fish tank. Read on to find out why your fish is!
Immobile Fish
There are many reasons why a fish may be staying in one spot. The main four reasons why a fish may stay in the same spot are:
- Temperature
- Sleep
- Odd circumstances
- Stress
These are the main four, which will be broken down into further subcategories as you read on.
Mainly, fish are constantly moving. If they aren’t moving at all or are staying in the same small area, it’s because they don’t want to be anywhere else in the tank. If this is happening, you should take notes on where they are, and why they may be there. There are some circumstances in why they are staying there that could mean that they are sick or that they are unhealthy.
Temperature
Some fish are native to parts of the ocean or sea that are colder or warmer, and this could be the reason why your fish is staying in the same spot of the tank. Heat, cold, and other factors could influence the temperature of the tan and would cause the fish to act differently,
Heat
Some fish like staying in either one side of the tank or the other because of the heat that the heater or the equipment gives off. If you get fish from a pet store, they may be accustomed to being in warmer water.
This would be due to being in a large environment that’s constantly lit. In some pet stores and public aquariums, they have specific heating lights to hover over the tank to constantly keep it warm in the whole tank.
Fish who were bred in the wild, need certain temperatures to stay comfortable. Fish that were bred in captivity generally don’t have a preference for heat. Whatever heat they were born in is what they will be more accustomed to.
For fish that were bred in the wild that like warmer water, would have been bred closer to the equator. These fish would generally be around the middle of the Pacific and Atlantic oceans, or in the northern Indian Ocean.
Cold
Fish who tend to like the colder temperatures will stay on the other side of the fish tank away from a heater or equipment that gives off heat. If you get your fish from a pet store, you’ll need to find out if they are compatible with being in warm water, or if they are only allowed in a colder tank.
Even though most fish from a store are accustomed to warmer water, there will be some who generally like the colder water and shouldn’t be mixed with warm water fish. Common cold-water fish include some species of goldfish, Paradise fish, crayfish, some shrimp, and more. This isn’t to say that cold-water fish don’t need some warmth.
Fish like this bred in captivity will breed closer to the north and south poles but closer to the south of the Indian, Pacific, and Atlantic oceans, as well as the north of the Pacific and Atlantic oceans.
Seasons That Change
Fish that live in the average water temperature zones may or may not migrate for winter. Most of the time, they won’t migrate due to the temperature, but because of the food source. Fish who eat smaller fish migrate because the smaller fish are leaving either because of the weather or because of a migrating season that all fish go through.
For fish that are in tanks or aquariums, they don’t have the ability to migrate. If they are colder because of the winter, they will tend to crowd around hotter parts of the tank. If the summer tends to heat up quite hot, then fish will stay away from the equipment or hide behind fixtures in the tank to avoid direct light.
Sleep
Fish may also be sleeping because they are asleep. Fish do sleep like any other creature they just do it differently than people do. Fish sleep with their eyes open because they don’t have any eyelids to close.
It’s hard to tell when fish are sleeping, however, when they do sleep, they move a lot slower than usual. They are never fully asleep, but they will move slowly when they are. They only stay moving when they sleep so they can keep water flowing over their gills so they can keep breathing.
If you see a fish that is sleeping, it isn’t fully asleep. Traditionally, fish sleep when it’s dark. In their natural habitat, they are awake when the sun is out, and asleep when the sun goes down. However, fish are never fully asleep. Their brain basically takes shifts in being awake. They are like this to help avoid predators in the night.
Predators have a form of night vision where they can see in the water. Fish stay still or hide in reefs to protect them from being seen. The less light that can reflect off of them in the night, the less chance they have of being seen.
Odd Circumstances
There a few odd circumstances in which a fish my be in a certain part of the tank and may not be moving. They may be at the top, bottom, or corner of the tank and don’t usually move more than a little at a time. They also may be staying in one spot of the tank more in the center of it, and there is a definite reason for this.
The Top of the Tank
If your fish is constantly staying at the top of the tank, it’s because the fish may not like the water quality. Meaning, that there is more oxygen towards the top of the tank and that most of the water may be dirty. The fish may also occasionally swim to the top and take breathes of air outside of the water for more oxygen. This means the tank is so dirty the fish can’t breathe in it.
The Bottom of the Tank
Some fish may stay around the bottom of the tank because of the quality of the equipment you are using. If the quality of the equipment is in poor condition, the filter may need cleaning, or the pH levels may be unbalanced. Other reasons why a fish may be continuously on the bottom of the tank is because of a sudden change in water temperature or because the tank is overcrowded.
There is a chance that your fish may be sick if it’s at the bottom of the tank. An imbalance in their bladder would cause this. Larger fish who eat too much and are fatter will have a harder time swimming upward because they aren’t strong enough to do so.
The Corner of the Tank
Fish will sit in the corner of their tanks, usually because they are stressed. Yes, fish can be stressed too. The reason why they are specifically at the corner of their tank is that they are unhappy with their environment. They might be wishing that they had more room to swim around or be in a different area altogether.
Another way to detect this is a thing called glass surfing. Glass surfing is like pacing. They swim back and forth because they are stressed about not having an adequate place to swim in. This could be because of the quality of the water or because the pH levels are imbalanced. They may also be doing this to try and escape water that is to warm or cold.
Stationary in an Enclosed Part of the Tank
Fish that stay in pieces of the tank or aquarium that has a lot of places to take shelter in are usually newer fish. Newer fish will do this because they are trying to hide. They are hiding because of their new environment. They could be skittish because of a new temperature or pH balance. They might simply be hiding because they are intimidated by new fish they are around.
In new tanks, fish may be intimidated by other fish. Sometimes, fish who have been in the same tank for a while may feel like they own that tank, and that it is their home. Fish can become dominant and even bully the new fish. If they are large enough, they may even eat the new fish because they might feel as if it needs to protect its home.
Stress
Fish get stressed just like we do. Their causes of why they might be caused are also just as normal as ours. Are you stressed from too much work, or not enough sleep, or even having to meeting new people? Fish go through these same things. As a result, fish will act differently than they usually will. In their case, you’ll be able to tell if they are stressed out.
In this, you will learn what causes the fish to be stressed, the symptoms of their stress and how to identify them, and how to fix what is stressing out the fish. After all, they have the same problem we do, so they can’t be that difficult to figure out.
General Symptoms
Four general symptoms emerge from stressed fish. They are:
- Gasping for air
- Loss of appetite
- Diseases
- Strange swimming patterns
Gasping for Air
As mentioned before, fish will swim to the surface and gasp for air out of the water. This is usually because they aren’t getting enough oxygen in their system to breathe properly. Most of the time, fish will do this because the water that they are in isn’t clean enough for them live in.
Another reason why they may be doing this is because of chemicals or medications that have been added to the water. They may not be used to it, and because they have some new it is causing them to stress. The air would be a coping mechanism to let them breathe fresh oxygen instead of what may be in the chemicals or medicine.
Loss of Appetite
Many things could cause fish to lose their appetite. By nature, fish are creatures of routine. If that routine is altered, they may not want to do anything and be so depressed that they won’t even eat. Other reasons they may lose appetite is due to an improper diet, and changes in their physical habitat.
Disease
Fish may become so stressed that they even get diseases. The biggest concern of most fish owners is the disease called Ichthyophthirius Multifiliis or Ich. Ich comes in the forms of small white spots on the fish. Ich is a disease that is a large array of parasitic attacks. Each white spot is a parasite attacking a fish.
Ich can do severe damage to a fish It can attack the skin and leave patches of skin missing from the fish. If the skin is attacked enough, it will damage the fish to the point of developing an ulcer, which is a large amount of pain. If it attacks the gills, it will make it harder for the fish to breathe. In either case, any fish that gets Ich will most likely end up dying.
This is merely one disease that they can get, but there are more such as cottonmouth, dropsy, fin or tail rot, fungal infections, and more.
Strange Swimming
When fish get overly stressed, they can swim in odd patterns. Mainly, this will be the highest stressful level that a fish can be at. They will swim very frantically, often going nowhere. They may also swim frantically into the tank walls or against things in the tank, like gravel or rocks. They will do this with their fins locked to their sides.
What can Cause these Symptoms
There are quite a lot of things that can cause these symptoms. If you keep the fish well cared for and the tank properly clean, you are easily able to avoid these things from happening.
Improper Conditions
Abnormal conditions of the tank are what causes fish to stress most of the time. This can either be the tank being dirtier than usual or a change in the pH balance of the tank.
This can be easily be avoided with proper and regular cleaning of the fish tank. Do your research or talk to a caretaker at your local pet store on how to keep the best environment for your fish, as this will play a large role in your fish’s life.
Trouble with Other Fish
New fish introduced into the tank can cause them to stress. First, the new fish is already scared enough of its new surroundings, and it will take time for it to adjust to its new environment. Worrying about other fish is common when you don’t have fish that were bred together or who have been around each other for a long time.
On the other hand, a new fish being introduced to a tank can cause the fish that are already there to stress. It can make the old fish want to hide from the new fish. It can also make some fish angry, and they may be inclined to bully the fish just because it is new. It will vary on whether the fish will be bullied based on the breed of the older fish.
Chemicals and Medicine
Chemicals and medicine can cause distress to fish on may levels. The new chemicals that get into the water are also chemicals that the fish might breathe in. This can cause a lot of problems for the fish. This would be like breathing in gas in your home for a while.
Even though medicine is meant to help make the fish better, it doesn’t mean that they like it. It’s as if you were a child being given medicine that you hated, but you had to take. Doing this to a fish without it knowing and just suddenly forced to stomach it can make it skittish and cause it to distress further.
Improper Diet
One of the most common ways that fish get distressed is if their diet isn’t controlled and steady. Although it doesn’t have the same effects, a varying diet can be the equivalent of eating fast food and fresh food back and forth. Some will make your body sluggish, and the other will do your body better.
Changes in the Habitat
If your fish is constantly in a state where their home is being changed around, they won’t understand where they are and will become confused. Confusion will cause the fish to stress. If you are changing the scenery in the fish tank, don’t do it very often
Another way that the fish get stressed is by being scared. When people bang or tap on the glass, it scares the fish a whole lot. This is the same for loud noises. Enough of this stress and panic from being scared will cause them to die.
There are a lot of factors that go into keeping a fish in a safe and steady environment. Make sure you do your part in keeping them as happy as stress-free as they can be. They’ll thank you for it.

Hi, my name is Adam and I’m an aquarium enthusiast! I didn’t discover the joys of being an ‘aquarium fanatic’ (as some of my friends call me!) until I was in my 20’s. When I first started out I found it difficult to find all the information I needed so I started this website to compile all the useful information I can think of. Enjoy!
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