How To Keep Angelfish From Fighting? (6 Quick Steps)

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So frequently, I noticed the known aggressive behavior among my angelfish. Sometimes things cooled down as time passed. However, there were times when the creatures tore each other’s fins.

Over the years, I’ve learned a few techniques to keep my angelfish from fighting. The key was to understand why that issue arose in the first place.

Keeping angelfish from fighting involves these steps:

  1. Make sure that your angelfish are indeed fighting and not mating.
  2. Separate the breeding pairs, which are naturally more aggressive.
  3. Raise your fish in relatively large tanks (22 gallons and over).
  4. Keep the angelfish in a group of five.
  5. Isolate the aggressive angelfish for a couple of days in a separate tank.
  6. Introduce plenty of vegetation to your aquarium.

These are the six steps I’ve found useful to reduce the aggression among my angelfish and prevent fighting. However, implementing those techniques is quite tricky. For that, I’ll go over each one and show you what I precisely tend to do.

Also Read: Why Has My Angelfish Become Aggressive?

Keeping Angelfish From Fighting

Angelfish are complicated creatures. The fact that they are fish means that it is difficult to control their violent behavior. You can’t exactly pull them apart every time they start fighting. More importantly, you can’t watch them all the time.

Unlike a dog, your tank can’t follow you wherever you go. Hence, if your angels are fighting, you have to take steps to resolve the issue once and for all. Otherwise, you might have to buy some new fish.

Naturally, it isn’t enough to know what causes fighting in angelfish. You must also take steps to resolve their issues. The steps you choose will depend on the cause you’ve identified, as I’ll discuss in the second part of this article.

1. Ensure Your Angelfish Actually Fight

First of all, you should realize that what looks like fighting among angels might actually be a sign of mating. When angelfish fight, they lock lips. But this is the same behavior you observe when a breeding pair forms in a tank.

You should take a moment to determine whether the angels are mating or fighting before you overreact. You can do this by figuring out the genders of your fish. If one of the aggressive angels is female, the chances that you have a breeding pair are quite high. 

Also, you should see what happens after the lip-locking. If the two angels eventually calm down and start swimming along for an extended period, they are probably mating. At a certain point, they’ll find a slate to lay eggs upon and reproduce.

2. Separate Breeding Pairs

The fact that your fish are spawning rather than fighting isn’t necessarily a good thing. As was mentioned above, spawning makes angelfish aggressive. To prevent the battle attracted by the presence of angelfish eggs and fry, you are encouraged to move the breeding pair to a separate tank. 

This way, they can get as territorial as they want without inconveniencing other angelfish. Of course, you could resolve this issue by preventing spawning in the first place. You can do this by keeping only male angelfish. Male angels can’t lay eggs. If your angels are all male, you never have to worry about eggs and fry.

3. Make Your Aquarium Roomier

You need to place your angels in a sizable tank. Keep in mind that the ideal size for a single, adult angelfish, is 22 gallons. You are encouraged to provide your angels with plenty of room to stretch their fins. Avoid overstocking by all means. 

Respectively, if you own several angels, you’ll need more than a 22-gallon tank. For each additional one, you’ll require twelve gallons more. You may also determine the right tank size by measuring the size of your angelfish.

4. Consider The Ideal Group Size

It is a bad idea to overcrowd your tank. This leads to fighting among your angels. However, it is also a bad idea to have a small number of angelfish. Small quantities encourage bullying.

This can happen when you have just three or even four angelfish. One or two angelfish will bully others. In a group of four, three angelfish could bully the fourth one. Every tank should have at least five angelfish.

This will spread the aggression, preventing one angelfish from being on the receiving end of all the violence. You don’t get quite as much fighting in large groups of angels, especially if they have a large tank.

Being in shoals also lowers energy consumption. When they swim next to each other, the angelfish enjoy the shared kinetic energy.

5. Prevent Territorial Behaviour

Angelfish will fight because they are territorial. One way to keep the peace is to eliminate the territories your angelfish have secured for themselves. To do this, you should take the angels out of the tank before re-arranging its layout.

Keep the aggressive ones in a separate tank for several days. Watch whether or not the remaining angels feel calmer and swim peacefully. When they do, put back those you’ve removed, and see if they have changed their attitude.

This should destroy the territories of the dominant fish, forcing all your angels to start over on a level playing field. In case it didn’t work, try removing other angelfish. Maybe you’ve picked the wrong ones in the first place.

6. Take Advantage of Vegetation

Don’t forget to fill your tank with foliage. If your docile angelfish are getting attacked by their more violent counterparts, give them some plants and decorations behind which they can hide.[1]

Fish typically stop attacking the moment the target of their aggression is out of sight. So you should give your fish a place to hide. This will provide the bullied inhabitants some much-needed relief while also allowing the aggressors to cool down. 

Are Your Angelfish Playing or Fighting?

Ordinary pets, such as dogs, are almost always within sight. As such, you can tell when they are fighting. You will either hear the commotion or eventually encounter them during a violent confrontation.

Angelfish are silent, and they can’t follow you around. As such, you can’t expect to witness every bit of fighting that happens in the tank. This is why you should look out for visible signs of conflict.

Look for wounds and marks of some sort on the bodies of your fish, such as nipped fins.[2] If you can identify the signs of fighting early enough, you can take steps to resolve the issue quickly. Also, this should raise your suspicions that your angels are indeed fighting and not just playing around.

Key Factors in Aggression Among Angelfish

When it comes to violence among angelfish, you have to keep a few factors in mind:

1. Fun & Entertainment

You need to understand what constitutes fighting. If your fish keep chasing one another around, that isn’t necessarily proof that conflict has broken out in the tank. There are other reasons for that.

Sometimes, they are just playing. Don’t be so quick to assume that your fish are fighting. Although, it is a different story if you notice bitten fins. In case your angelfish hurt each other, it is a different story.

2. Territory Establishment

Angelfish are territorial creatures. This attribute becomes even more pronounced when they start mating. It isn’t that uncommon for angelfish to act violently towards creatures that have invaded their territory, including fellow angelfish. 

But in such cases, the aggressive behavior typically stops once the invading fish has retreated. So the aggression manifested here isn’t always a cause for concern. Generally, it is better to observe patiently.

3. Aggressive Characteristics

Sometimes, aggressive behavior in angelfish isn’t a sign of actual aggression. But in some cases, it is exactly what it looks like. Bullying is far more common among fish than you might realize. It isn’t that uncommon for larger angelfish to assault smaller angelfish. 

The cause of this behavior isn’t always easy to identify. You can assume that a fish is being bullied if it keeps choosing isolation, particularly during meal times. Once you start introducing food to the tank, if one fish stays away while all the others eat, you probably have cause for concern.

In some cases, an angelfish will retreat the moment other angelfish enter its vicinity. If you have hiding places, it will use them to stay out of sight. Such cowering is a sign that fighting or bullying has been happening in the tank.

Why do Angelfish Fight?

You shouldn’t overreact to every manifestation of aggression. However, fighting isn’t healthy among your fish, and you should always endeavor to stop it before your angels suffer real harm.

Some people can’t imagine their angelfish fighting. And once they finally witness such behavior, they have no idea how to keep it from happening. The best starting point in such situations is to determine why the fighting is happening in the first place. 

Potential causes typically include the following:

1. Hierarchy Establishment

Angelfish have hierarchies. Every group has a leader that others are expected to follow. To establish this pecking order, conflict of some sort typically ensues. Whether or not such fighting should worry you depends on the situation.

The objective is for one fish to prove that it is stronger than its rivals. In many cases, once a pecking order has been established, and one fish has risen to the top, the fighting will subside. You won’t see quite as many altercations.

However, there are times when a pecking order is established, but the fighting persists all the same. In such cases, you have every reason to worry. This is where bullying enters the picture. 

If one angelfish has proven its supremacy, but it is still attacking the other angels, you have to step in. It means that there are additional factors to consider that might be responsible for the aggression.

2. Relatively Small Tanks

Angelfish fry are not that hard to rear. They are so tiny that you don’t need much in the way of space. Most people can get away with an appropriately sized bowl. Unfortunately, too many fish owners buy tanks based on the sizes of the young angels they are raising at present.

They do not consider the growth the fish will undergo down the line. As a result, they eventually end up with tanks that are simply too small for adult-sized angelfish. A small container is going to encourage angelfish to fight. 

First of all, they have no way of staying out of each other’s territories. Secondly, small tanks will convince them that the resources available are limited and that they have to fight to ensure their survival. 

When it comes to angelfish, keep in mind that it takes twelve months for the fry to mature. That is, of course, when the conditions are ideal.

3. High Numbers

The easiest way to encourage fighting in angelfish is to overstock your tank. There is no point in buying a large aquarium if you have too many angelfish. Again, it is an issue of territory and resources. Your angels will react to the perceived scarcity by engaging in combat.

It is also worth noting that overcrowding can cause stress in angelfish. And stress can lead to violence. Keep this in mind, when trying to determine the number of angelfish you should keep in the same tank.

4. Spawning & Breeding

Most angelfish become aggressive when spawning. They have an overwhelming desire to protect their young. This makes them very territorial. Sometimes, their aggression is justified, especially if the other angels keep attacking their eggs and fry. 

But sometimes, they are acting irrationally. They might even attack their own pairing mate. Either way, if your angelfish are spawning, you should expect some fighting to occur. 

5. Lack of Food

Like all pets, fish must be fed. You shouldn’t overfeed them because that will make them sick. However, if you underfeed them, they will fight. As was mentioned above, angels react negatively to a perceived scarcity of resources.

If you start genuinely limiting the available resources in the tank by failing to feed your angels in the appropriate amounts, you will incite violence, and not just during mealtimes. 


Fighting and aggression among angelfish are prevalent issues. However, sometimes lip-locking and nibbling are merely a matter of entertainment. The best way to distinguish between the two is by observation. If your angels show signs of damage, like nips on the fins, you should act to stop it.

Solving the problem mainly focuses on reducing stress. You may do it by providing your angels with a large tank with plenty of vegetation. Also, you should avoid overcrowding your tank. Keeping them in groups of five is probably in your best interest.

I hope my article helped you in any way. The bottom line here is experimenting. Try a few techniques and see what works best in your tank. Either way, I wish you the best of luck.