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How to Keep Angelfish from Breeding? (7 Easy Steps)

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As you might have already read, I own a 20-gallon tank. Usually, my fish live in harmony. However, my angelfish tend to breed quite frequently and overcrowd my tank. Over the years, I started looking for ways to keep my angelfish from breeding. I came to realize that if I don’t take any actions, the delicate balance in my aquarium will be ruined.

Keeping angelfish from breeding involves these steps:

  1. Grow your angelfish in relatively small tanks – preferably 20 gallons and below.
  2. Avoid the ideal pH levels for breeding (6.5-6.9) by using alkalizing techniques.
  3. Stick to high-flow filters, which will tire your angelfish.
  4. Avoid plants and driftwood that angelfish are likely to spawn eggs upon.
  5. Put a spawning slate in your tank and remove it once the female laid eggs on it.
  6. Introduce a single-gender of angelfish – preferably males.
  7. Grow competitive companions along with your angelfish.

These steps might help you avoid angelfish’ breeding. However, some of them may also harm your adult fish and cause unnecessary issues. Keep on reading to understand better how to achieve the desired, delicate balance. 

How to Stop Angelfish From Breeding

People love angelfish because of their unique appearance, which includes bold stripes and long fins. For most people, the fact that they are so easy to breed is what makes angelfish so attractive. 

Obviously, you have to maintain the right conditions in their tank. However, angelfish are more forgiving than most other fish, capable of surviving in a variety of conditions.

Therefore, if you just want to enjoy the few angelfish you bought from the store and have no interest in increasing their numbers, the fact that they breed quickly is going to irk you.

No one would blame you if you chose to let them breed as they please. After all, you can choose to sell off or eliminate the offspring they eventually bring into the world. But some people prefer to stop their fish from breeding in the first place.

For beginners, this idea seems ludicrous. Can you actually stop angelfish from breeding? Yes, you can. But the approach you choose to take will vary depending on your means, preferences, and situation. 

To figure out the best way to stop breeding, you must first consider the conditions angelfish require to reproduce. If you can identify these conditions, you can experiment until you find a way to dissuade them from spawning.

‘Experimentation’ is the perfect word to use here because you have no way of knowing what will work and what won’t. And because fish are generally sensitive creatures, you are encouraged to apply caution:

1. Stick to Small Tanks (Below 20 Gallons)

Proper breeding requires a large tank. This is what most experts say. Depending on the number of fish you have, you are encouraged to secure a tank that is at least 20 gallons.

It takes time to acquire the right tank and to get the water to the right state to support breeding. Typically, it will take a few months to get the habitat ready before you can start worrying about breeding.

This assumes that you want breeding to happen. Because of their size, angelfish need plenty of space to maneuver. A small tank is going to make them feel stressed. And once that happens, they might fail to spawn. This is because they no longer feel secure. 

If you don’t own a small tank, you might find my aquarium kits buyer’s guide useful. I’ve included there a section that discusses a 5-gallon package that received hundreds of positive reviews over the years.

Try to remember that breeding in angelfish has two stages.[1] First, the female fish must lay the eggs. Secondly, the male fish has to fertilize them. A cramped tank will induce considerable stress. But it won’t stop the female fish from laying eggs. 

Some breeders will tell you that a smaller tank prevented their fish from laying their eggs. But those occurrences are few, so you shouldn’t count on them. The chances of your female fish laying its eggs even in the face of undue stress are quite high. 

However, that same stress has a higher chance of preventing the male fish from fertilizing the eggs. And if the male doesn’t fertilize the eggs, they will never become living fish.

Again, this is an experiment. There is no way of knowing how your fish will react to this situation. Some males are so resilient that they will successfully fertilize their eggs in the face of cramped conditions.

Do not count on this approach to deliver results in every single situation. You should also know that cramped conditions encourage violence among angelfish.

If you start to notice signs of aggression because of the size of the tank, consider changing tactics. This also applies to situations where your angelfish are breeding successfully regardless of the tank’s volume.

2. Avoid Ideal pH Levels (6.5-6.9)

Angelfish are strong creatures. They can survive a wide range of conditions in their water. However, to encourage breeding, you need to maintain the pH within the right range (6.5-6.9).[2] 

Breeders typically have tools that they use to test the pH in their tanks. In cases where the pH isn’t ideal, they will use a filter (de-ionization or reverse osmosis) to remedy this situation. 

So naturally, if you want to stop breeding, you can try altering the pH. Because they prefer to live in soft, slightly acidic water, if you modify the acidity (or alkalinity) too drastically, your fish could fail to breed.

Now, this probably seems attractive because it sounds like a straightforward means of preventing breeding. By changing the water to the right pH, you are directly prohibiting reproduction in angelfish. However, this method is also quite experimental. In fact, it requires a significant amount of caution.

Yes, the wrong pH will prevent breeding. But no one can tell you for sure what this anti-breeding pH is. Why is this a problem? The answer is simple: the wrong pH can interfere with angelfish survival, especially if the alteration is extremely drastic. So, determine whether or not you are willing to compromise the health of your fish to find the right pH.

In truth, if the lives of your fish do not concern you, then extensive experimentation will eventually allow you to identify the right pH. But again, you must be prepared to lose your fish. 

In other words, the results you discover will only serve the angelfish you acquire down the line. But your new fish might not react the same way to the changes in pH as your old fish. 

This warning also applies to people who think that they can prohibit breeding through temperature changes. Angelfish can tolerate various temperatures, but they tend to thrive within a particular range (78-86 Degrees Fahrenheit). So lowering or raising the temperature could create enough discomfort to prevent breeding. 

However, you can still harm your fish in the process. If you wish to control the temperature the best way possible, you may read my review regarding the aquarium heater I use. That was the only heater that didn’t make the temperature fluctuate during the day and made experiments like this possible.

3. Use High-Flow Filters

The filter you choose matters. Experts encourage the use of sponge filters because they can control the levels of nitrites and ammonia in the water without harming younger fish. So what would the wrong filter do?

Even though angelfish can tolerate strong currents, a high flow filter could tire them out, making the breeding process a little more difficult. The best ‘Hang on the Back’ Filters, Internal Filters, and Power Heads have a mechanism that allows you to control the strength of the flow.[3]

If that doesn’t sound impressive, the wrong filters can play a different role. They will trap your angelfish fry. As such, every time you clean out the filter, you are permanently eliminating unwanted fry. It is worth reiterating the fact that this requires cautious experimentation.

A flow that is so strong it practically pushes your fish around can’t be healthy for them. In fact, the water flow isn’t the best tool for stopping breeding. You are better off relying on filters that can trap fry.

4. Avoid Plants And Driftwood

If you have owned angelfish for quite a while, you probably know that, on occasion, the males will fail to fertilize the female’s eggs because of a lack of privacy. They are easily distracted. 

For this reason, you are encouraged to dissuade people from knocking on the tank’s glass and taking pictures. You may also provide plants and driftwood behind the fish can hide to feel secure. This will allow them to focus on the task of fertilizing their eggs.

By not providing these secure locations, you can potentially disrupt the breeding process. Now, as you might have guessed, this approach doesn’t work all the time, and it doesn’t work with all angelfish. 

Some angelfish are more focused than others. This is the sort of method you use when you are desperate or as a means of complementing other approaches. On the other hand, you are less likely to harm the fish.

On a side note, angelfish should be fed appropriately to encourage breeding. However, you can’t overfeed them. Doing so to your angelfish will bring them considerable harm. So the dieting factor isn’t worth considering.[4]

5. Take Advantage of Spawning Slates

A lot of breeders will tell you that if you have more than one angelfish in a tank, you have no way of definitively preventing them from breeding. You can slow them down or complicate the process. But the chances of your fish eventually finding a way to breed are quite high.

If you have concluded that breeding among your angelfish is unavoidable, you still have a card to play. Start by giving your fish a suitable breeding location.[5] Spawning slates are not that hard to come by. Insert the slate (a flower pot can also work) into the tank.

Make sure that it is leaning against the wall of the tank at a 30-degree angle. Your angelfish will identify this as a suitable breeding ground. When the female lays its eggs, take the slate out and discard the eggs. To ensure success, you need to insert multiple spawning slates

Give your fish as many suitable breeding locations as possible. They will eventually select one of them. This method requires vigilance. But it is guaranteed to work. Even if your fish lays its eggs on another surface beside the spawning slate, you can still retrieve them. Angelfish eggs take two or three days to hatch. So you have time.

6. Grow Merely Male Angelfish

If the idea of identifying, retrieving, and destroying the eggs is too much work for you, you have one another method that is guaranteed to work. Keep female fish out of your tank. Breeding requires male and female angelfish.

You can choose to keep only female angelfish in your tank. Without the males, any eggs that have been laid will never hatch because they haven’t been fertilized. However, female fish present a challenge. As was mentioned above, they can still lay eggs in the absence of a male angelfish.

And as you might have heard, angelfish get aggressive and territorial when they are breeding. They have been known to attack other fish in an effort to keep their eggs safe.

Breeders who have encountered such situations will tell you how difficult it can become to maintain peace in your tank. Some breeders are forced to move their angelfish to separate containers to prevent further aggression.

Such headaches are worth suffering if you intend to breed angelfish. The fry that eventually hatches is often worth all the trouble you had to endure.

However, if you don’t want to breed angelfish, you are going to hate these violent occurrences because they serve no purpose. For this reason, you are better off sticking with a male angelfish.

You don’t lose anything with this gender because they look just like the females, but they don’t lay eggs. Of course, the fact that they look so much like the females means that identifying the gender might present a challenge. Then again, if you are buying your fish from a store, you can just ask the seller to give you a male fish.

Not only is this the easiest way to prevent breeding, but it is the safest and most harmless. It also guarantees results. There is zero chance of breeding happening in a tank with only male angelfish. 

If you think that you only have male angelfish in your tank, but then you start to observe fry in the water, you probably made a mistake. One of your fish is a female, and you must identify and remove it before further breeding occurs.

7. Introduce Competitive Companions

If you have a small number of angelfish in a tank, the chances of breeding happening are quite high. But if your angelfish live in a tank with numerous other fish, especially aggressive species, you can count on them to either eat the eggs or the fry that eventually hatch.

This approach doesn’t guarantee total success, but it will drastically reduce the number of young angelfish being added to the tank. Do not overcrowd your tank. Find a quantity that controls the number of angelfish being hatched without crowding the tank so thoroughly that violence erupts. 

You should also cautiously choose the types of fish you introduce to the tank. Avoid species that might threaten your adult angelfish. 

You can also achieve the same result by introducing more angelfish. 

They will happily eat other angelfish eggs and fry. In fact, angelfish tend to eat their own eggs and fry. This is why many breeders take them out of the tank. They feel the need to protect these young ones from their parents. By letting natural selection happen, you can save yourself a lot of trouble.


Keeping angelfish from breeding is a challenging task since some of the steps might harm your adult fish. The safe ways would be introducing merely male angelfish and removing the spawning slates once the females had laid eggs upon it.

The rest of the mentioned steps should be done with cautious. However, they are still valid. Experiencing over and over again is the only way to know for sure.


  6. Featured Image: Flickr