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Why Angelfish Stay at the Bottom of the Tank (8 Common Reasons)

Why Angelfish Stay at the Bottom of the Tank (8 Common Reasons)

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Sometimes you might get worried about your angelfish when they start acting strangely. Typically, angelfish are going to be rather active fish.

They usually spend a lot of time swimming around, but you’ll feel concerned if the fish just stay at the bottom of the tank. Surely this has to be a sign that something is wrong with the fish, right?

Read on to learn about some of the common reasons why an angelfish will stay at the bottom of the fish tank. This should help you to determine what might be happening in your situation.

It’s possible that you might be able to make some changes so that the fish will be more active again. Once you’ve learned everything that you need to know about this topic, you’ll have a much better idea of how to proceed.

This Isn’t Typical for Angelfish

The first thing to know is that staying at the bottom of the tank isn’t typical for angelfish. This isn’t normal behavior, and this means that something is probably wrong with the fish.

You might notice that the angelfish appears to be lethargic and isn’t moving around as much. This signifies that the fish might be sick or dealing with some other issues.

Below, you’ll learn more about potential reasons why angelfish will swim at the bottom of the tank. Just know that this isn’t healthy behavior for the fish.

It actually isn’t healthy for angelfish to swim at the bottom of the tank. Under normal circumstances, angelfish would spend most of their time in the middle of the tank or near the top of the tank.

In all likelihood, there is something wrong with the tank or the fish itself. You’ll just need to take the time to figure out what is going on so that you can try to get things back to normal.

1 – The Angelfish Could Be Getting Old

A Pair of Marble Angelfish

One thing to consider before going further is the age of the angelfish. If you’re caring for a very old angelfish, then it might be swimming near the bottom of the tank due to a lack of energy.

As fish get older, they’re going to be less and less energetic. Angelfish can live for quite a long time when you care for them well, too.

It’s possible for an angelfish to live up to ten years in a fish tank. This is a very long time, and you should be proud of yourself if you took care of an angelfish long enough for it to get this old.

If the angelfish in question is quite old, then you might not have anything to worry about. It could simply be that the fish is getting old and tired.

Now, you should be aware that this could be an indication that the fish might not live much longer. Sadly, an angelfish is going to reach a point where it will die of old age if it sticks around long enough.

There are many other things that can cause angelfish to stay at the bottom of the tank, though. If your fish is only a few years old, then it’s likely that you’re dealing with another problem.

2 – The Angelfish Could Be Stressed

Stress is something that negatively impacts fish. Not every new fish tank owner thinks about the stress that the fish experience.

When angelfish experience stress, it makes it harder for them to live happily. In fact, a stressed angelfish might wind up having a compromised immune system.

This will make the angelfish more prone to contracting diseases. Also, general stress will make the fish more lethargic than usual even if it isn’t sick.

Thus, it’s possible that your angelfish is simply stressed, and that is why it’s sticking to swimming at the bottom of the tank. There are many things that can cause an angelfish to become stressed that you should be aware of.

Fish get stressed when you transfer them to new tanks. This can’t be helped, and you’ll just need to give the fish a bit of time to get acclimated to a new tank.

Noises can cause angelfish to experience a great deal of stress. If your fish tank is in a noisy section of your house, then that could be stressing the fish a lot.

People tapping on the glass of the aquarium will scare the fish and make them stressed. If you have children, then you should do your best to keep them from tapping on the glass for the sake of the fish.

Other pets such as cats might do the same thing. Cats might paw at the glass and scare the fish if you don’t keep the cats from being able to get near the fish tank.

Even something such as harsh lighting can cause fish to stress. You want the fish to be able to experience more of a normal day and night cycle rather than having to deal with bright lights at all times.

Finally, water quality issues could be a factor. You’ll learn more about that in a bit.

3 – Aggressive Tank Mates

Angelfish in a Community Tank

Aggressive tank mates might cause the angelfish stress. You could have other fish in the tank that are bullying and injuring the angelfish.

This could make the angelfish feel as if they need to stay toward the bottom of the tank to try to stay safe. You simply might not have done a good job of picking compatible tank mates for the angelfish.

Do a bit of research to see if the fish in your tank are supposed to get along. If you have fish that aren’t compatible, then you might want to move certain fish to another tank.

It’s even possible that angelfish could be fighting each other. Two male angelfish in the same tank will not be able to get along well.

Males will fight over territory, potential mates, food, and many other things. It’s generally recommended to avoid putting two males in the same tank.

You can sometimes get away with it if you put two males in a very large fish tank. This makes it easier for the male fish to stay out of each other’s way.

Knowing all of this, you should be able to determine if aggressive tank mates are causing your fish to stay at the bottom of the tank. If this is the case, then you should be able to solve the problem easily enough.

4 – Water Quality Problems

There are a variety of things that can go wrong with the water quality in your tank. When the water quality isn’t what it needs to be, it will have an impact on the health of the fish in your tank.

Your angelfish could be sick or stressed due to problems with the water in the tank. Determining exactly what is wrong might take some time since you’ll need to check all of the possibilities.

Firstly, you should take a look at the temperature of the water. It’s generally recommended to keep angelfish in water that ranges from 76 degrees Fahrenheit to 84 degrees Fahrenheit.

If the temperature of the water is off, then it might make the fish sluggish. When the temperature is really far from the recommended range, it could cause the fish to die.

The pH balance of the water is supposed to stay between 6.8 and 7.8. You’ll need to use a pH testing kit to ensure that everything is in the right range.

As a fish tank owner, you’re supposed to check the pH balance of the water every so often. If you’re new to caring for fish, then you might have overlooked this and made a mistake.

5 – Issues with Toxins

Angelfish in Cloudy Water

Issues with toxins can cause angelfish to experience many complications. Nitrate, nitrites, and ammonia are very harmful to your fish.

You want to do your best to remove toxins from the tank. The best thing to do is to buy a biological filter that can help to keep the water as safe as possible.

Certain aquatic plants will also help to get rid of ammonia. It’s a good idea to have aquatic plants in the fish tank because it will help the angelfish to feel more comfortable, too.

Be careful if you suspect that toxins are a big issue in your fish tank. Check your filter and try to ensure that it’s doing its job or you might need to buy a new one.

If the fish are being impacted by toxins, then you should know that the fish will become listless and much weaker than usual. You might also notice discoloration as well as problems with appetite.

In extreme cases, the fish might wind up gasping. Be on the lookout and you should be able to prevent this from becoming a problem.

6 – Crowded Fish Tanks

Putting too many fish in a tiny fish tank is not going to be a good idea. It can be dangerous in some ways, but it can also cause the fish to feel stressed.

Generally, angelfish are going to do better when they’re placed in tanks that give them more than enough room to swim around. You might buy a big enough tank to start, but you could make the mistake of filling the tank with too many fish.

If things get too crowded, then the angelfish might feel forced to stay at the bottom of the tank due to the presence of so many other fish. Even if this isn’t the issue, you should know that a crowded tank can cause problems with oxygen.

A lack of oxygen in the tank due to overcrowding will be unfortunate. This can also make it easier for toxins to become a problem in the aquarium.

Only add new fish to the tank if you know that you have enough room. Otherwise, it’d be better to buy a separate tank for any new fish that you wish to purchase.

7 – The Angelfish Could Be Sick

Freshwater Angelfish With White Spots Indicative of Ich Disease

The angelfish might be staying at the bottom of the tank due to being sick. Sick angelfish are going to be far more sluggish than usual.

There are many different sicknesses and diseases that angelfish will have to contend with. Some of the common ones include dropsy, swim bladder disease, and ich.

All of these diseases are serious, and you’ll want to get the fish treatment as soon as you can. Looking out for signs of disease will be a good idea if you want to keep your fish alive.

Of course, keeping the tank clean and caring for the fish to the best of your ability will lessen the likelihood that angelfish will get sick at all. If you do a good job of keeping the water parameters in the right range, then you likely won’t deal with too many issues with sickness.

It is possible to bring sick fish into your tank accidentally, though. You could buy a new fish from a pet store that has ich without realizing it.

This is why it’s generally recommended to quarantine new fish for six weeks before adding them to the main tank. It helps to keep you from spreading diseases to the fish in your aquarium.

Doing the same thing for aquatic plants will be wise, too. Live plants can carry bacteria that can get fish sick.

If you quarantine the plants in water that has no fish for several weeks, then you can add them to your main tank without having to worry. Just be mindful of the potential for things to go wrong so that you can act accordingly.

When you discover that your fish is sick, you’ll be able to treat the fish. If you catch things early enough, then the fish should be able to survive and get back to normal.

In some cases, the disease will have progressed too far. Some fish tank owners will also choose to euthanize fish to prevent illnesses from spreading to other fish in the tank.

You might want to seek out specific advice from an exotic veterinarian. This will give you a chance to truly determine the best course of action.

8 – Angelfish Do Sleep at the Bottom of the Tank During the Night

Another thing to know is that it will be fine to notice the angelfish at the bottom of the tank during the night. When the lights are off, the angelfish are going to take some time to go to sleep at the bottom of the tank.

Some might debate whether or not what the angelfish are doing can be called sleep. The angelfish enter a resting state where they are still alert enough to react at a moment’s notice.

During this time, the colors of the fish will fade, and the angelfish will stop moving for a time. You might be a little scared if you see the fish this way because you will worry that it has died.

Many people mistake sleeping fish for dead ones. It’s pretty easy to tell the difference, though.

You can simply try to get the fish’s attention to see if it is still alive. If you attempt to scoop the fish up with a net, then it’s going to react in some way if it’s alive.

This is just to show you that there are instances where fish will be at the bottom of the tank while nothing is wrong. It’s just that most people don’t notice the fish doing this since it’s at night when they’re sleeping.

Final Thoughts

There are many things that can cause your fish to want to stay at the bottom of the tank. Fish will sleep at the bottom of the tank at night, but it isn’t normal for them to stay at the bottom of the tank at all times.

If your fish seems to be remaining near the bottom of the aquarium, then it’s likely that something is wrong with it or the tank itself. It could be that the fish is sick or stressed, but it could also be related to water quality issues.

You should check the water quality so that you can figure out if anything is amiss. It should be easy enough to make some changes if you need to.

Also, you should observe the fish to try to determine if it is sick or not. If the fish shows any signs of illness, then you might wish to contact an exotic veterinarian for assistance.

This is the easiest way to identify what is wrong with the fish. Otherwise, you can look up specific information about fish diseases such as dropsy and swim bladder disease to try to figure out what’s going on with your fish.

Hopefully, this information will allow you to take care of your fish better. You might be able to solve this problem so that the fish will start swimming in the other parts of the tank as normal.

Simply do your best to take care of your fish and things should turn out fine. Let your friends know why angelfish might stay at the bottom of the aquarium if they’ve been encountering these same issues.

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Vickie Thomas

Friday 20th of October 2023

I'm not sure what is going on with my angel fish is seems to be struggling to swim he just staying at the bottom and not moving