Why is Angelfish Not Eating?

Angelfish are typically hardy fish, but they occasionally experience some health issues. These health problems will always arrive with specific symptoms that often foretell the disorder’s nature. One of them is an unexplained low appetite, among a bunch of other signs. In some cases, the fish will stop eating completely.

However, there’s a problem here. The lack of appetite can hint at several disorders, including no disorder at all. Fish are known to refuse food if they’re stressed, for instance. The same goes for all symptoms; they are all standard in a variety of conditions, making the diagnosis process delicate and prone to misinterpretations.

So, understanding why your angelfish has decided to refuse food suddenly is critical to prevent potentially deadly problems. Today, we will dive into the angelfish’s most common situations that will cause the fish to stop eating.

7 Reasons Angelfish is Not Eating

There are a variety of reasons why angelfish would refuse food, and not all of them are health-related. The following are the most common causes to consider:

– Aggressive Mates

Angelfish are cichlids, so it’s only natural that they possess some aggression in their genes. These fish rank as semi-aggressive, which means they won’t necessarily go out of their way to bully or attack other fish.

But they do care about their personal space and territorial delimitations. Angelfish are occasionally prone to violence against their tankmates, especially when eating, mating, or reinforcing their territorial boundaries.

That being said, angelfish only grow up to 3-4 inches at most, even with optimal care. So, they aren’t too imposing, to begin with. Larger and more aggressive species will bully the angelfish and can intimidate them, either by sheer size or a colorful and volcanic personality.

Fish like Red Tail sharks, more aggressive species of cichlids, pufferfish, or other violent companions can bully, hurt, or even kill the angelfish.

And that’s not the only danger. Famous fin nippers like tetras can also stress the angelfish, although the former are half the cichlid’s size. Tetras rely on their speed and numbers to achieve their goals of annoying their tankmates.

When stressed, the angelfish will naturally seek to leave the area and go into hiding to catch its breath. If the stress is too much, it will begin to affect the angelfish’s behavior. The fish will stop eating, become more irritable, apathetic, and even grow more vulnerable to health issues due to a weaker immune system.

Choosing the angelfish’s tankmates carefully to prevent this scenario.

– Poor Water Parameters

We need to address the elephant in the aquarium here since most people have an incomplete notion of what water parameters stand for. They tend to think in terms of temperature, pH, and water hardness, but the big picture is…bigger than that. In reality, the notion of water parameters also includes aspects like:

  • Lighting – Your angelfish require a natural day/night cycle to regulate their biological rhythm. You should have a lighting system in place to provide the fish with a steady day/night cycle. Otherwise, your fish won’t be able to rest properly and will become stressed as a result.
  • Plants and decorations – This refers to the tank’s layout. Angelfish require a natural-looking setting with plenty of plants, rocks, and various other decorations. These will serve them well during moments of stress, fear, tiredness, and even during the breeding period.
  • Steady water flow – Angelfish come from the Amazon’s natural slow-flowing waters, so they don’t appreciate aggressive water currents. Make sure that the filtration system is stable and kept at moderate flow for a calmer yet healthy and well-oxygenated habitat.
  • Sandy substrate – Many aquarists ignore the importance of the substrate and go for whatever pleases them, esthetically speaking. They should go with what pleases the fish instead. Since it’s a cichlid, the angelfish loves to bury itself in the substrate occasionally. It gives the fish a sense of meaning and comfort. Not that I can read the angelfish’s mind, but that’s what the fish does in the wild, so the conclusion comes rather naturally.

Other than that, the rest of the tank water conditions are pretty standard. As a tropical fish, the angelfish needs:

  • Water temperature revolving around 75 to 82 °F
  • Water pH between 6.8 and 7.0
  • Water hardness between 4 and 12 GH
  • Clean, healthy, and well-oxygenated waters (aka tank maintenance and regular water changes are necessary)

In short, the angelfish requires a stable and healthy environment that preferably mimics the conditions in its natural habitat.

– Sick Angelfish

With very few exceptions, the angelfish will display similar early symptoms when sick, no matter the disorder’s nature. The hiding behavior is one such symptom, as are the lack of appetite and the apparent apathy. However, these symptoms alone can’t explain the condition your angelfish is struggling with decisively. More investigation is necessary for that.

As a result, you should:

  • Quarantine the fish – This is a necessary step since you have no way of knowing whether the condition is contagious or not. Quarantining the angelfish in a hospital tank will protect the rest of the aquatic life and give you time to understand the problem.
  • Diagnose the issue accurately – This may be tricky, especially since you’re against time. Most fish disorders are deadly in advanced phases, and many will progress fast with minimal warning signs, if any. That being said, different disorders will eventually showcase specific signs that will be indicative of the condition’s nature.
  • Offer targeted treatment – Some basic treatment methods apply to most fish conditions. Increasing the tank’s temperature is one since it increases the fish’s comfort and can affect the life cycle of various skin parasites. Adding salt to the tank water is also good for boosting the fish’s mucus production and promoting natural healing. Antibiotics may also be necessary in case of parasitic or bacterial infections.

Either way, if your angelfish shows signs of sickness, you should assess its condition immediately. Quarantine the fish even if there are no worrying signs of any dangerous illness. Some disorders will progress rather fast, despite starting of slow and seemingly innocuous.

– Don’t Like the Food

If your angelfish doesn’t like the food, it won’t eat it. It’s as simple as it sounds. Angelfish are omnivorous fish that will consume a variety of foods. They need both protein and plant-based foods to provide them with a balanced nutrient intake. They are also less fussy than other fish when it comes to their food. So, they will eat everything, whether they are flakes, pellets, live food, etc.

So, if your fish spits out the food or simply refuses to eat it, consider the following:

  • It’s not right for them – Some fish foods may not be fitting for your fish. It doesn’t matter whether the food is nutritionally optimal. Your fish may simply not like the taste since different fish foods have different flavors. To test that, you should change the food and see whether your angelfish likes another product.
  • It’s expired – This can happen at times since feeding your fish daily can develop into a steady routine fast. In some cases, people forget to keep track of the food’s expiration date. The food may not become dangerous when expired, but it may lose its flavor with time. Make sure you check the label once in a while since expired food can eventually turn deadly.
  • It’s chemically unsafe – This usually happens with live food or food that has been contaminated in some manner. Many people will feed their angelfish insects and worms caught in the wild, which is a no-no. Wild insects and worms often carry deadly parasites and bacteria that will infect and kill your fish. If that doesn’t happen, they can also carry pollutants and chemicals that will enter the fish’s system with similar results.
  • Not the right size – Angelfish are generally medium-sized, measuring around 3 to 4 inches. However, they are way smaller than that in their juvenile phase, around 1.5 to 2 inches. Feeding them oversized pellets and flakes could backfire since the fish won’t be able to eat them. Make sure that the food can fit their mouths, otherwise, your fish will experience a lot of teasing and no nutrients.

– Internal Parasites

Internal parasites aren’t necessarily deadly, except they tell a darker story. Many of these parasites are already swimming freely in the tank water. The only reason why they aren’t infecting your fish yet is the fish’s immune system. Healthy fish possess a natural barrier against parasites and bacteria, but this isn’t failproof.

If your fish is stressed or lives in poor water conditions, its immune system will suffer. This will leave the fish vulnerable to parasites and a potential infection. You may not be able to diagnose the disorder at first, but it should become obvious over time.

The fish will stop eating as its abdomen swells up, visible with no apparent cause. Camallanus worms are generally the culprits when it comes to internal worms.

– Protecting the Eggs

This point is a bit more difficult to consider since angelfish aren’t exactly your perfect parents. They will often eat the eggs and even the fry upon hatching. This is why most aquarists will rely on nursing tanks to grow the fry and remove the parents once the eggs have been fertilized.

However, some angelfish will protect their eggs rather fiercely against other fish. So much so that they will even refrain from eating, just to keep a close eye on them. The eggs, I mean. Don’t worry, though, the fish will resume its normal eating pattern shortly. So long as there are no signs of a health condition, your angelfish’s fasting period isn’t a reason for concern.

– Overcrowded Tank

Angelfish are semi-aggressive, which means they will carefully choose their opportunity for violence. Food competition is one of them. Stacking too many angelfish in the same tank can and will affect their mental state. They will become more aggressive and stressed and may exhibit worrying behavior, such as hiding, refusing food, or appearing apathetic.

All these are symptoms of fish stress that could have more drastic long-term consequences when ignored. To prevent that, consider each fish’s space requirements.

One angelfish needs approximately 20 gallons of space since these are active and rather territorial creatures. You then need to increase the tank’s size by 10 gallons with each new angelfish you’re bringing into the picture.

Angelfish need room to roam their environment and feel comfortable and safe. Otherwise, they might become cranky and snap at their tankmates more often.

Are Angelfish Picky Eaters?

No, angelfish aren’t really picky eaters. If they’re hungry, they will eat whatever you feed them. That being said, angelfish do have preferences. They are different individuals that will often display different preferences.

I recommend starting with normal fish food and seeing what they like and what they avoid. They sometimes refuse a type of food because they don’t like the taste of it.

How Long Can Angelfish Go Without Eating?

Angelfish can go without food for various lengths of time, depending on the fish. For the most part, they can refrain from eating for about 3 days without experiencing any meaningful health issues. However, some may go longer than that, while others not so much.

It all depends on factors like the fish’s age, health, and general appetite. Angelfish are quite capable of going through several days of fasting since food isn’t always available in the wild. This being said, I suggest providing your fish with a stable diet and 2 meals per day consistently. It’s not worth testing its limits since you can never tell how your angelfish will react to a forced fasting period.

Why is Angelfish Not Eating and Hiding?

If your fish isn’t eating and hides around the tank, consider the following issues:

  • Aggressive tankmates stressing the fish and forcing it into hiding
  • Parasites or other illnesses
  • Digestive problems like constipation due to overfeeding
  • Poor water condition affecting the fish’s appetite and behavior
  • Overcrowding leading to increased aggression, stress, and bullying
  • Low water temperatures affecting the angelfish’s metabolism and digestive system

As you can see, there may be a handful of potential problems. You can only identify the correct issue by assessing it more in-depth and preferably soon to keep your fish safe.

How to Get Your Angelfish to Eat?

If your angelfish isn’t eating, but there’s nothing wrong with it, consider the following solutions:

  • Diversify the diet – Maybe your angelfish doesn’t like a specific food but loves another. Play around with various food options to see which appeals to your angelfish the most. You should feed the angelfish a varied diet of animal protein and veggies and plants for optimal nutrient intake.
  • Monitor water parameters – If water parameters aren’t ideal, your angelfish might feel stressed and refuse to eat. Keep the water temperature stable, perform regular maintenance, and avoid strong water currents. These measures should reinstate your fish’s appetite pretty fast.
  • Eliminate aggression – If there’s tension in the tank between fish, consider mitigating the violence and improving their dynamics. You can do so by adding more plants and decorative elements to keep the fish calm and comfortable. If this doesn’t work, you should remove the aggressor from the environment.

If your fish is healthy and the only thing that’s bothering you is its refusal to eat, these methods should work. Also, consider that the fish may be stressed if it’s a new addition to your tank. So, it needs some time to adapt to its new setting. It’s common for angelfish to refuse food during this time.

Don’t worry, your fish will begin to eat again shortly.


Angelfish typically have a healthy appetite. If your angelfish refuses to eat, there’s always something at play that needs investigation. In most cases, the situation has easy fixes. In others, you may need to put in more effort to make sure your fish regains its healthy appetite.

Fortunately, you now have this article as your competent ally along the way.

avatar Noah
I’m Noah, chief editor at VIVO Pets and the proud owner of a playful, energetic husky (Max). I’ve been a volunteer at Rex Animal Rescue for over 2 years. I love learning and writing about different animals that can be kept as pets. read more...

Leave a Comment

Your email address will not be published. Required fields are marked *