Goldfish Staying In The Corner Of Their Tank? (All Causes)

Last Updated on 2023-05-24

There are a number of different reasons your goldfish may be staying in the corner of their tank. And oftentimes, it’s going to be the sign of something wrong in their environment.

The main reason that your goldfish will stay in the corner of their tank is due to stress. Stress which is often caused by a tank which is overcrowded, poor water temperature, poor water conditions, and sickness.

In this article, you’ll find out all the main causes, as well as things you can do to set them right as well!

Why Is Your Goldfish Staying In The Corner Of Their Tank? (And What To Do!)

Here are all the different reasons that your goldfish is going to be staying in the corner of their tank! As well as the things you can do to help get them swimming around happily again!

In most cases, whatever the cause, the underlying problem is going to be stress. And there are so many things that cause stress. One coping mechanism goldfish have when they’re stressed is backing into a corner to feel safe.

Unfortunately, stress is one of the hardest problems to fix because there are so many things that cause it! Therefore, it’s important to find out the cause of stress! Here are some of the most common causes of stress are:

Being Added To Their Tank

One reason all fish get stressed is when they’re added to their tank for the first time. You have to remember, they’ve probably been transported in a small bag for a good amount of time, they’re in a new environment, and the water parameters are going to be different from what they’re used to.


Unfortunately, there’s not much you can do about this. One great tip is to add API Stress Coat to the tank when you first get them. It’s a water conditioner that also has added aloe vera, which helps reduce stress in goldfish.

Apart from this, though, you should just leave them on their own and keep the light off for a few hours to help them feel safer. If you do this, they should start swimming around the tank after a few hours to a couple of days!

The Tank Is Overcrowded

You should also make sure that your tank isn’t overcrowded! Especially with other semi-aggressive or aggressive fish. When your tank is overcrowded, your goldfish may feel like they don’t have enough space of their own or that they’re always watching their back.


If the tank is overcrowded or you have aggressive fish in the tank, then you’ll need to either get a larger tank or remove the aggressive fish. Remember, a single goldfish need at least 30 gallons. After this, every goldfish you add will need another 10 gallons!

And when there are aggressive fish in the tank, the best thing to do is remove them. If you can’t remove them, try adding lots of plants and decorations to break lines of sight. And finally, if this doesn’t work, put a tank divider in.


Sometimes your goldfish may just prefer a corner of the tank over other places. Maybe it’s because it’s more sheltered or that there’s more algae growth near it. Perhaps, it happens that you often tend to feed them from that corner, so they linger there.


No matter what it is, if it’s your only preference, you don’t need to worry. However, you should keep an eye on them to make sure it’s not a sign of something more serious.

If you still want your goldfish to swim around the tank, there are a couple of things you can do. The best thing is to try and make it more inviting. This could mean adding lots of new decorations and plants. Or adding tank mates that are going to be compatible with your goldfish!

The Water Temperature Is Being Dispersed Properly

Different goldfish are going to need different water temperatures to be happy. Generally, most goldfish like temperatures between 68-74°F. (However, the temperature range does vary from fish to fish.)

If you have a heater on one side of your tank, and your tank is large, then the heat may not be getting dispersed properly. Some areas of the tank may be too hot or too cold, so your goldfish is going to the corner that’s the right temperature for them.


If you think this is the case, then try moving the thermometer in your tank to different areas. Give it a few minutes, and then check to see if the temperature is different. If you notice the heat isn’t being dispersed evenly, then you should add another heater to balance things out.

The Temperature Is Too High Or Low

If the temperature is too high or too low, then your goldfish may move to one of the bottom corners of the tank. Up to a certain point, warm water rises, so your goldfish may swim to one of the bottom corners to where it’s cooler.

However, also, as water starts to go close to freezing, the cold water will sit on the top, and the warmer water will be at the bottom, having the same effect as before.

Likewise, when water is too warm, there isn’t going to be as much oxygen in it, so your goldfish may be swimming to the bottom to breathe easier.


The easiest way to solve this problem is to buy purchasing a reliable heater that will heat the tank. You want to make sure your heater can heat the whole tank but won’t overheat. The heaters I always recommend are Fluval M Series. They’re relatively cheap while still being extremely reliable!

Related Reading:

Ammonia Poisoning

Ammonia poisoning is extremely serious, and if you think that your goldfish is suffering from it, you’ll need to act fast to save them.

It occurs when there’s too much ammonia, nitrites, and nitrates in the tank. When it happens, it can often happen fast and kill your goldfish in a matter of hours. If your goldfish is at the bottom or top corner of a tank, gasping for air, then it could well be ammonia poisoning. As well as this, you may also notice that their gills are red too.


If you think it’s ammonia poisoning, you should test the water immediately. When there’s too much ammonia, immediately perform a 50% water change. (If you don’t have a test kit, then you should perform a 50% water change anyway and buy one.)

Sometimes, even after a water change, the ammonia levels may still be too high. If this is the case, then add some API Ammo Lock to neutralize it.

You can also reduce the chance of ammonia poisoning happening by cycling your tank before adding goldfish. This means you leave the tank empty for a few weeks while you let the beneficial bacteria that eat ammonia grow.

As well as this, you should also make sure that you’re not overstocking the tank, you’re changing the water regularly, and that you’re removing any waste from the tank.

betta care facebook group

The Water Flow Is Too Strong

If you’ve got goldfish, then a filter is essential for keeping the tank clean. However, sometimes the water coming out of the filter can be too fast. When this happens, your goldfish will probably stick to areas that the current isn’t so strong. One such area is the corners of the tank.


If this is the case, you can do a couple of things. First of all, you can try to angle the filter into the side of the tank to reduce its flow through the middle. Secondly, you can add a filter sponge to the filter nozzle to reduce the rate water comes out.

And, of course, you should only do both things after checking your filter. Sometimes filters have a switch that lets you choose how powerful the flow speed is.

Your Goldfish Is Sick

When your goldfish is sick, they may back up into a corner to make themselves feel safer. They do this because they feel vulnerable, so they’re trying to cover their backs.

It’s best to check your fish for any signs of disease to make sure this isn’t what’s causing the behavior. Lethargy, clamped fins, and a lack of appetite are some common symptoms of illness. But each disease will also have more specific signs. For example, if it’s ich, you’ll notice white spots over their bodies; when they’re constipated, they may look bloated, if it’s swim bladder disease, they may be on their side, and if it’s dropsy, they may have pinecone scales.

Whatever the case may be, you’ll need to diagnose the illness where possible and treat it immediately.

You can also prevent illness by keeping the tank clean, performing frequent water changes, quarantining new fish, and feeding your goldfish high-quality food.

They’re Full Of Eggs

Sometimes female goldfish may stay in the corner of the tank when they’re full of eggs. Just like sickness, they stay in the corner because they feel vulnerable. Unfortunately, there’s not much you can do for this one except wait for it to pass.

Not Enough Hiding Places

Lastly, they may be doing it because there aren’t enough hiding places in the tank—all fish like lots of hiding places where they can feel safe and rest. Without them, they’ll attempt to feel safe by backing up into a corner.


You can remedy this easily. All you have to do is add lots of plants and decorations to the tank. Your goldfish can then pick their favorite areas to feel safe.

Here’s a video explaining the different goldfish behaviors and what they usually mean.


Now you know all the different reasons your goldfish might be backing up into a corner! You should also know how to stop it from happening as well. If you liked this article, check out the rest of the website! Otherwise, have a great day!

If you liked this article, make sure you check out the rest of the website!

Ultimate Betta Fish Care Guide
About the author

Hey! I'm Nicolas from Iguane Media !

Blogger and Owner of the betta care fish guide
Thanks for reading this blog

I'm an Animal Lover