why is my angelfish not eating?

Why Has My Angelfish Stopped Eating?

(Last Updated On: February 22, 2023)

It’s worrying when your angelfish refuse to eat or don’t seem to be able to do so. The reality is, there are several causes, and any one of them can affect your fish. That’s why you’ll need to undertake some detective work to find out what’s bothering them.

Illness and nutritional deficiencies are some of the most common reasons why fish stop eating. Fish need various foods, including those rich in protein, to stay healthy and maintain their appetite. Poor water conditions, stress, and unsuitable environmental factors are predominantly responsible for your fish’s lack of appetite. Aggressive fish and stress are other causes and can both cause long-term damage. 

Fish can starve to death if they’re physically unable to eat. That’s why you must treat the situation seriously to get to the bottom of the problem as quickly as you can.

Why Is My Angelfish Not Eating?

Fish are hard-wired to eat when they’re hungry. When they stop feeding, there’s a reason for it. Unfortunately, as we’ve already mentioned, prolonged periods of not eating will eventually cause your angelfish to starve to death, so you must work to find a speedy resolution to preserve their lives.

If you’re wondering what does it means when your fish stops eating, these are the most likely reasons:

Poor Water Conditions

Even though angelfish are tolerant of slight changes to the water, they can’t deal with sudden or significant surges in water quality. Fluctuating chemical levels can cause the angelfish to stop eating before they die.

In particular, rising ammonia levels are a problem in all fish tanks. While it’s found in most aquariums, it affects all fish negatively when they rise too much. Harmful ammonia levels are caused by:

  • New, uncycled tanks
  • Excess fish excrement
  • Over-stocked aquariums
  • Over-feeding

According to Global Agriculture Alliance, decomposing matter also contributes to poor water conditions. This includes rotting food, dying plants, and dead fish.

why angelfish won't eat

No Food Variety

Wild angelfish eat a variety of foods. They’re omnivores, so they feast on live prey, including shrimp and other fish. However, in most aquariums, owners only feed them flakes and pellets. Over time, they get bored of consuming the same thing day in, day out, and stop eating entirely.

The Journal of Applied Biological Sciences explains how angelfish show a preference towards meat because they need high protein levels. Therefore, incorporating worms and insects into your angelfish’s diet provides advanced nutrition and mental enrichment. 

Similarly, try adding vegetables, such as zucchini, peas, and cucumber, to keep your angelfish interested in food and encourage them to keep eating. As a rule of thumb:

  • Feed 60% to 70% of staple food, such as flakes and pellets.
  • Feed 30% to 40% of other foods, such as meat and vegetables.

Vitamin Deficiencies

Angelfish that are not fed a healthy, balanced diet are at risk of vitamin deficiencies. This commonly leads to a decrease in appetite. If you feed your angelfish the right foods, they shouldn’t need liquid supplements. However, to encourage your fish to start eating and ensure they’re healthy, add supplements to the water to help increase their appetite. You can get these from any pet store selling live fish or accessories.


Appetite loss is usually one of the first signs of illness. Some conditions leave angelfish physically unable to eat because of the pain and discomfort. The most common illnesses to affect angelfish include:

If you suspect your fish are sick, look out for other symptoms, such as poor swimming abilities, gasping at the water’s surface, and a change in appearance.

If your fish have any of these health conditions, quarantine them into their own tank so that they don’t make the other fish sick, particularly if they’re suffering from parasites or bacterial infections, as these are more likely to be contagious.

Environmental Changes

If your angelfish’s environment isn’t sufficient, they’ll lose their appetite. Getting the parameters right in your tank is a complex process. You’re at risk of aquarium conditions souring if you don’t regularly test the water to check the chemical levels accurately. Angelfish also lose their appetite because of:

  • The incorrect temperature
  • Evaporation
  • Too much light or darkness
  • Insufficient tank size – i.e., it’s either too big or small.
  • Low oxygen levels

Another problem is a lack of territory. Angelfish are territorial and like to claim specific rocks and plants as their own. Rearranging the environment is sometimes necessary to prevent aggressive, dominant fish from taking over, but it can confuse and stress fish, ruining their appetite.

Aggressive Fish

Unlike other cichlids, angelfish are relatively peaceful. They can be aggressive towards each other during mating season, but otherwise, they’re happy to live with other fish. Because of their peaceful nature, they’re at risk of becoming bullied by larger, more dominant fish. This will cause them to lose their appetite.

Similarly, if angelfish have to compete for food, the weaker ones in the tank will stop altogether. If there’s not enough food, they’ll chase each other to get the last traces of food. This is why some angelfish stop eating – there’s not enough food.


Stress is a leading factor of appetite loss. Angelfish are easily stressed and become affected by:

  • Too much activity within the tank
  • Overcrowding
  • Bad water conditions
  • Not enough hiding places

If your angelfish only skip a meal, it’s not too much to worry about. But if they refuse other meals, this situation requires your urgent attention. To help increase your fish’s appetite, offer it new, unfamiliar meals, such as live food to hunt or frozen food that you’ve thawed. Protein-rich flakes are also hard for angelfish to resist.


A lack of dietary fiber, poor-quality foods, and inadequate nutrition are the leading causes of constipation. It makes life feel very uncomfortable for fish, so they lose the ability to eat.

Peas are an excellent natural way to ease constipation. They’re higher in fiber than other vegetables and flush out the system. Feed any fish suffering from constipation one boiled pea, removing as much of the outer shell as possible. Angelfish love peas and should eat them without intervention.

How Long Can Angelfish Survive Without Food?

Healthy adult angelfish are able to survive for three days without food. Young angelfish don’t fare as well and only survive for a day or less.

In the wild, angelfish are used to going a few days without food. That’s because they have to hunt and forage to eat, and food doesn’t come around every day.  

However, it’s not healthy for angelfish to go for too long without eating. If there’s a shortage of food, they’ll become aggressive and fight with each other. This can lead to injuries. Because of starvation, angelfish become lethargic, sickly, and dim in color. In the most severe cases, angelfish may consume other fish in the tank or fry to survive.

How Much Food Do Angelfish Need?

Angelfish should eat twice a day. Watch how much your fish eat within two minutes, and then use this amount as their ideal portion size.

Juvenile angelfish need more nutrients to grow and develop. As a result, you should feed them 3-4 times a day. At first, fry need more live food and later have flakes and pellets.

How Do You Know if You’re Not Feeding Your Fish Enough?

Angelfish are experts at hiding when something’s wrong. If you’re not able to determine how much your fish are eating as you feed them, you’ll need to look for tell-tale signs instead. These include:

Weight Loss

Weight loss seems like an obvious symptom of under-eating, but it can be hard to spot. Angelfish are known for their slender appearance, but they’re likely not eating if they become too thin.

Taking pictures every day is an excellent way to tell whether your fish have lost any weight. That being said, even well-fed angelfish are slender, so don’t rely on this method alone to determine whether your fish have stopped eating. By the time you’ve ascertained your fish aren’t eating, it could already be too late.

Appearance Changes

Sickly, malnourished fish will experience changes in their appearance. Your fish’s diet plays a large part in their coloration. If they don’t get the vitamins, minerals, and nutrients they need to stay healthy, their scales suffer.

In fact, nutritional deficiencies are responsible for turning fish white. That’s because some foods, such as those containing shrimp meal, lutein, and Spirulina algae, are natural pigment enhancers that bring out the colors of the fish. As soon as your fish stop eating, their colors may fade, making them look visibly sick. While this isn’t good for the fish, it can help you spot when something’s wrong.

Breathing rapidly

Fish that are breathing rapidly are suffering from either long-term stress or a health condition. This suggests that your fish are suffocating – possibly due to low dissolved oxygen levels. In this case, fish aren’t interested in eating or are physically unable to do so.

This is a worrying sign. If you don’t solve the issue as quickly as you can, your fish will die soon after.


If any of your fish are secluding and isolating themselves from their tank mates, they’re likely sick. Parasites and bacterial infections are most likely to blame for this. By keeping itself secluded, the fish minimizes the risk of the disease or infection spreading throughout the tank.

You should quarantine any sick fish into a separate tank until you’re able to cure it of its health condition. Eventually, you can encourage them to eat and regain their strength.


Fish without an appetite are more likely to hide. You’ll find them hiding in the corner of the tank or amongst plants and decorative accessories. There are many reasons why angelfish do this, including:

  • Predatory fish
  • Aggressive companions
  • Poor water conditions
  • Hard water
  • Tank overcrowding
  • Sickness

All of these things are linked to appetite loss and refusal to eat, causing problems for your fish.


Bloating isn’t one of the most obvious signs that a fish has stopped eating. However, it goes hand in hand with health conditions responsible for appetite loss. Bloat is commonly the result of bacterial infections, protozoan infections, constipation, and dropsy.

Reducing stress and carrying out a water change is the first step in treating your fish, but your vet will also recommend an appropriate treatment.

Food in the Tank

If you can’t determine whether your fish aren’t eating through their appearance or behavior, look for signs of uneaten food at the bottom of the tank. Angelfish rarely safe food for later, so if they don’t eat when you first feed them, they won’t eat at all.

If you don’t remove the food as soon as you see it, it will rot and raise the tank’s ammonia to harmful levels. This will kill your fish in only a short space of time.

how long can angelfish survive without food?

How Do I Get My Fish To Eat?

If your angelfish stop eating, you must try all you can to get them to start again. It won’t be easy, and you may need to contact your vet for advice, but you can do things to make conditions in the aquarium more suitable. These things include:

Remove Stressors

To minimize your fish’s stress and prevent any reason for them to lose their appetite, remove all stressors from the tank. This includes chemicals, such as ammonia and nitrites, decaying plants and food, and controlling aggressive fish. If there aren’t enough plants in the tank providing hiding spots, add more plants or decorative features.

Vary the Diet

If you’ve been feeding your fish the same food for a while, trying to vary the diet and see how well they respond. You might find that a simple switch is all your fish need, solving the problem. If they take well to this, swap their food out a couple of times a week to keep them interested.

Similarly, swap between frozen and fresh foods, as this will offer a wider variety of textures. If you’re able to, provide live foods for your fish to hunt. This doesn’t only offer optimum nutrition but mental stimulation, preventing stress.

Feed the Right Amount

Feeding your angelfish the right amount of food is tricky. Under or over-feeding your fish means that some of the fish in your tank become inadequately fed. As a result, your fish haven’t chosen not to eat but can’t get access to the food in the tank.

To ensure all fish have a fair chance, only offer your fish enough food they can eat in two minutes. If they eat quicker than this, you haven’t fed them enough. If they eat everything faster than this, you’re not feeding them enough. If there’s food left in the tank, you’ve fed them too much.

Reset the Territory

If you’re dealing with dominant angelfish that stress the weaker fish out and prevent them from eating, reset the territory. This involves moving the plants and decorative features to new spots within the tank.

Sometimes, it helps to reset the boundaries and enables weaker fish to find their own territory. If conditions worsen after you’ve done this, moving some of the items back to where they originally were.

It’s no doubt stressful when fish stop eating, but in some cases, improving conditions is enough to improve their appetites. If it continues for more than a day, something’s wrong. Take your fish to the vet for professional treatment before they die.