Why have my fish stopped eating

Why have my fish stopped eating? 5 Reasons

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There are times when your fish simply stop eating. After you panic, stop and ask yourself this question: What caused this sudden lack of appetite? The answer is: incorrect food, crowded conditions, fish disease, poor water condition, temperature or weather change. We will get more detailes:

Incorrect food

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When your fish stop eating, the first thing to do is to make sure that you’re giving them the correct food for their species. For example, large goldfish need pellet foods that float. If you are only feeding them algae discs, they will not thrive. On the other hand, bottomfeeding catfish would appreciate the same disc.

Top feeders like danios do best on floating and flake foods. If you’re feeding them the wrong thing, switch to the proper food immediately. If the problem persists, read on for other causes.

Food variety

Although it is not a bad idea, it is not an excellent way to feed the fish with only one type of food because feeding on just one mixture regularly is just as monotonous to our fish as it will be to us. Bear in mind that some species are vegetarian.

Mollies, barbs, zebras and ‘algae eaters’ are examples even though some still consume other foods in great proportions. As can be seen, keeping natural plants in the aquarium is worth it

despite the experience of seeing leaves sometimes littering the aquarium bed and/or floating in the water, something many aquarists and hobbyists see as unpleasant.

Some fish like nosefish, electric-catfish and reedfish (also called snakefish) may not take every kind of dry foods partly because they are predatory, living chiefly on crustaceans and insects in the natural.

In the long run, experienced fishkeepers can tell ifsome fish might not delight on dry foods but still make wonderful pets in the aquarium.

Crowded conditions

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Overcrowding causes stress and encourages excessive competition for food. Normal eaters may become shy or frightened and not get their share of the food.

My Fish Stopped Eating Because Of Disease

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Fish stop eating regularly as they start to drop off physically.

Some common diseases that confront the aquarists include white spots, ulcers, sunburn and sliminess of the skin


Ulcer is caused by bacteria and can form any where on the skin and it exposes the flesh which often looks bloody and causes more damage to the skin as the fish scratches on gravels or stones, or by some rough handling. Fish in this condition should be separated from healthy ones.

Sliminess of the skin

Sliminess of the skin is caused by heavy infections of tiny parasites which irritates the skin of the fish causing them to scratch their bodies on surfaces, which then increases mucus formations and giving the skin a slimy, grey appearance.

There are anti-parasites solutions for treatment which can be found in many aquarium stores.

Sun burn

Sun burn: It is believed that this problem occurs when the ultra violet rays of the sun have direct effect on the fish. It could as well be from excessive lighting of the aquarium (imagine the use of a 40 watts light bulb for 30 litre tank).

The symptoms include the burning and ulceration of the top of the head and the fins if proper care is not taken. Sun burn can also lead to fungal or bacterial infection. One remedy is to provide shade in the aquarium by stocking it with plants without choking up the swimming space.

Poor water conditions

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Polluted water and other bad aquarium conditions can have a major effect on your fish’s normal feeding habits. Also check the temperature and pH and nitrate levels if your fish suddenly stop feeding.

Water and filtration

Just as a good atmospheric condition is vital to animals on land, so is the water layer to fish as long as it is clean and unpolluted.

We can classify the water available to us into three forms: tap water, rain water and fresh water. Natural fresh water is good for use in aquariums but there is the danger of the water containing parasites and diseases.

Tap water which is the most available in many urban areas contains dissolved chlorine which could be harmful to fish when used immediately; but when aerated or even stored and exposed for about 24 hours, it matures for use as most of the chlorine would have dissipated.

Rain water is great and is probably the purest form of natural water. It is basically clean and well-oxygenated but may be polluted by chemicals in the atmosphere or by the collecting containers.

Chlorinated water

Chlorine is a halogen and is a highly efficient disinfectant and in many countries, it is added to public water supplies to kill agents that cause diseases (bacteria, viruses, etc.).

These agents commonly grow and thrive in public water supply reservoirs, on the walls of water conduits and in storage tanks.

When the chlorine is present in small quantity, it may affect the life of the fish negatively and this may cause breathing difficulties, lack of adequate growth, or even very poor breeding capability.

One solution is to aerate the tap water (e.g. overnight) which will expel the chlorine as gas. This method works but be aware that you can easily buy water conditioners from the store. They are sometimes called anti-chlorine and are added to the water in prescribed measures.

The oxygen need

Like all other animals, fish need oxygen and they breathe by extracting oxygen from the water, which they take through their mouths and pass over the capillaries in their gills from where it is absorbed into their blood stream.

Carbon dioxide is given out through the gill flaps. Remember that apart from the natural process of oxygen dissolving into the water, air is also supplied into the water by the airpump via installed accessories like airstones, filters and other air-powered decorations.

The air supplied into the aquarium has three basic functions:

1. Provides a moving power for the functioning of air-driven accessories.

2. Provides oxygen, remove carbon dioxide and break down toxic waste by its contact with water.

3. Induce water movement and generate turbulence as in natural water. So indeed, aquariums without decorations and accessories that can create action within the water are a little boring!

Fish give off carbon dioxide and if this gas is dissolved in large quantity, it becomes dangerous to the fish.

This is why aquariums which do not have air supply should not be kept where they will suffer inadequate ventilation or oxygen deficiency. Otherwise you will often find your fish close to the water surface with their fins folded and gasping in atmospheric oxygen.

At this point they will not feed and will not be active, and if this condition persists for a long time, they will invariable suffocate and/or die.

In addition, it is a very bad idea to overstock the aquarium simply because you cherish keeping a variety of fish. This will lead to the fish gasping for air when aeration is not at its best.

Temperature or weather changes

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Hotter weather may mean a decrease in oxygen in the aquarium’s water. If this is a problem, add an extra airstone (to split the air into smaller bubbles) or install a power head (which you can purchase at your local pet shop) on your undergravel filter. You will find more information on aquarium equipment in Aquarium equipment articles.

So remember, the fact that your fish are not eating may not be caused by improper feeding conditions. You need to take other factors into consideration as well.

Some fish refuse to eat just because they’re picky. There may be no other reason than that. Try different types of food until you find one they are happy with.

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