What to do when your fish is dying

Why your fish is dying?

It is very unpleasant when fish begin to die in the aquarium. It would seem that everything was done correctly: clean water is poured, the aquarium equipment is working, the fish receive food on time. Despite this, living creatures die. Unfortunately, this situation occurs quite often among newcomers to the aquarium business, which is why it is necessary to arm yourself with the knowledge of the causes of this phenomenon.

Every novice aquarist should understand in advance the following: if conditions are created for its inhabitants in a water house that is as close as possible to their natural habitat, then they will not get sick, let alone die.
At the very least, the risk of death will be minimized.

Fish is dying by nitrogen poisoning

Practice shows that in the overwhelming majority of fish dying is caused not at all by some external diseases, but by mistakes in the care, illiteracy, and carelessness of their owners. There are various reasons for this unfortunate phenomenon or a combination of some factors and reasons that can be considered in detail.

Reasons: Proteins, which make up a significant part of fish food, consist of amino acids that contain at least one amino group (NH2 group). In the process of digesting food in fish, proteins are broken down, converted into amino acids, which in turn form homologous proteins that serve as “building blocks” in the construction of the fish organism.

The remaining amino acids are freed from the amino group and must be excreted as a result of metabolism. The released amino group is converted into ammonia (NH3) and is excreted from the fish body mainly through the gills, a small part of the ammonia is excreted through the kidneys. Ammonia is a strong poison that is fatal to fish even in small concentrations (LD50 = 0.5 mg / l). It must be immediately removed from the aquarium using a filter unit and must never exceed a concentration of 0.01 mg / l, otherwise, it will lead to chronic physiological disturbances in the fish.

Symptoms: Due to the lack of oxygen, the fish constantly stay on the surface, gasping for air, and their breathing is noticeably difficult. When such fish are opened, pale gills, partially covered with spots, immediately rush into the eyes.

Current: The sensitive parts of the gills are especially damaged. In chronic poisoning with ammonia and nitrites, usually, the monolayer epithelium of the gills grows strongly, becoming stratified. Gas exchange between blood and water is very difficult, practically nullifying. For the same reason, it is difficult to remove the corresponding metabolic products through the gills. The outer parts of the stratified branchial epithelium no longer communicate directly with the blood and provide an ideal breeding ground for various bacteria (Flexibacter).

Ammonia is harmful to fish even in very low concentrations (over 0.2 mg / l), and at a concentration of 0.5 mg / l it already leads to death (LD50 = 0.5 mg / l). In the aquarium, its concentration should not exceed 0.01 mg / l, otherwise, after a while it will lead to chronic damage to the gills.

Research methods: If a pestilence begins and the fish is dying swimming in the murky water of the aquarium, breathing difficulties are noticeable, then the ammonia content in the water should be measured.

Treatment: If acute ammonia or nitrite poisoning occurs as a result of a power outage, the fish should be immediately transplanted into fresh water. In an overcrowded aquarium, where the ammonia concentration is quite high, the fish have become accustomed to these conditions over time. Abrupt transplanting them into fresh water will mean certain death for them. Therefore, in such cases, it is recommended to carry out enhanced aeration and install an additional water intake filter, due to which toxic nitrogen compounds will slowly be converted into nitrates and the fish will have time to get used to the new conditions. Fish should not be fed during this time.

In all cases of poisoning with ammonium or nitrite compounds after reducing the toxic concentration – on the one hand, by replacing the water in case of acute poisoning, and on the other hand, by installing additional filtering devices in case of chronic poisoning – the aquarium and filter should be

empty and clean. This will eliminate oxygen-scavenging substances and maintain ammonia oxidation. In addition, you need to find out what causes the increase in the content of poisons in the aquarium. If the cause was a power outage, then in this case everything is quite simple. But most often there is a whole complex of factors influencing each other (overpopulation, overfeeding, a large amount of food debris or the presence of dead fish in the aquarium water, etc.) that upset the ecological balance in the aquarium.

Prevention: To prevent ammonia and nitrite poisoning, it is recommended to check on filter performance, tank capacity, number of fish, and amount of food. Food debris, detritus, and dead fish should be completely removed as they reduce the oxygen content of the aquarium water. The reduction of organic matter in aquarium water is ensured by the high oxygen content of the water, adequate filtration, and suitable filter material. In addition, food should be given to fish in such quantities that they can eat everything completely in a short time.

Features: Nitrate, as an end product of nitrification for fish, is relatively harmless. However, sensitive fish or lower animals (invertebrates) do better in seawater if the water is nitrate-free. Especially lower marine animals react very painfully to nitrates and feel good and reproduce normally only in water without nitrates.

It is too expensive to remove nitrates from salt water either by using an ion exchanger (apparatus or chemical) or by changing the water. It is much cheaper and more thorough to eliminate nitrates by a bacterial method.

Buy compressed activated charcoal (regular activated charcoal does not work!) For a regular car engine filter as a filter material and put charcoal briquettes in oxygen-rich aquarium water. Inside these briquettes, an oxygen-free environment is maintained, since, due to very small pores in the coal, oxygen penetrates into the coal slowly, and bacteria manage to use it to destroy the organic carbon compounds absorbed by the activated carbon. If there is no more free oxygen physically dissolved in water, bacteria use oxygen chemically bound in nitrate to break down organic compounds. In this case, the nitrate is converted into elemental nitrogen (reduction reaction).

Effect of the concentration of oxygen dissolved in aquarium water on fish

Water aeration

Most aquarium fish (except for the labyrinth and some other species) need forced pumping of water with air (or rather oxygen) using an air pump.

The smaller the aquarium or the larger the number of fish in it, the more intensive the pumping should be.
To not ask question about what to do when your fish is dying in a fish tank for inexperienced hobbyists learn about violation of the oxygen regime in the aquarium.

As already mentioned, the water in the aquarium must be aerated around the clock. Otherwise, oxygen starvation and fish death may occur.
This is especially pronounced in fish that are in a small volume and in large quantities (for example, in a fifty-liter aquarium, after half an hour, a lack of oxygen in a flock of barbs is clearly noticeable).

Signs of oxygen starvation in fish in an aquarium

How to determine when oxygen starvation (anoxia) occurs in aquarium inhabitants?
The main sign of a lack of oxygen is, first of all, the presence of fish directly near the surface of the water and its frequent swallowing of atmospheric air. It is at this moment that the gills are burned, which leads to irreversible processes.

It should be borne in mind that the amount of oxygen consumed by the fish increases significantly after feeding and at elevated water temperatures, as well as at night, especially if there are live plants in the aquarium.

How to prevent oxygen starvation of fish

In order to prevent oxygen starvation in your aquariums, you should:

  • to pump water with oxygen around the clock using an air pump, if this is not possible, then turn it on at least overnight;
  • do not overpopulate the aquarium with fish;
  • often (at least once a week) change the water to fresh;
  • it is advisable to use turbine filters with a compressor function;
  • to organize the circulation of water in the aquarium using a filter pump.

What to do when your fish is dying from lack of oxygen

What to do if a picture is already observed when all the fish are at the surface of the water and greedily swallow air?
It is necessary:

  • urgently replace at least a third of the water with fresh water. If the aquarium has a volume of more than 100 liters, then you can use water directly from the tap, heated to room temperature;
  • increase the oxygen pumping of water by connecting another air pump;
  • if possible, place the fish in other containers, preferably with a small layer of water, and organize good aeration.
  • in the most extreme case, you can add concentrated hydrogen peroxide at the rate of one or two drops per three liters of water (this can be done no more than once!), or use special imported chemicals to increase the oxygen concentration in water.

What to do when your fish is dying

The excessively high concentration of oxygen dissolved in water

Now it is necessary to say about another negative process – an excess of oxygen in the water.

This is usually observed during the day in small aquariums heavily overgrown with plants, in which, moreover, powerful aeration is organized, or with a single change of a very large amount of fresh, oxygenated water.
This is very harmful to fish and can lead to gas embolism, when gas bubbles form in the blood of fish, and ultimately to their death.
Therefore, what to do when your fish is dying:

  • change water in small portions;
  • optimally choose the composition of fish and the number of living plants in the aquarium;
  • adjust the air flow from the compressor to a medium level.

Fish is dying because of disease

There are hundreds of diseases inherent in the inhabitants of the aquarium, and no fewer reasons for their occurrence, however, the main reason for the health problems in aquarium fish is one – it is bad or inappropriate conditions of detention, these include:

  • the aquarium is in a state of disrepair: the water has not been renewed for a long time, it has become cloudy, and is heavily contaminated with organic waste (food residues, excrement, etc.)
  • fish live in unsuitable water: for example, soft instead of hard or acidic instead of neutral
  • the aquarium is insufficiently or poorly equipped: for example, no shelter, too bright lighting, high or low water temperature, cramped conditions, etc.
  • the behavioral features of different fish species forced to live together are not taken into account: for example, peace-loving species live together with predators, the presence of several territorial, schooling fish living alone, etc.
  • unsuitable or spoiled food, inappropriate diet: for example, herbivorous fish do not receive herbal supplements, and predators live on a dry food diet.

All of the above external factors negatively affect the well-being of fish, lead to a decrease in immunity, and, as a result, to an increased risk of infection with various pathogenic bacteria or microorganisms.

Before a disease can be treated, it must be diagnosed.

O2 deficiency

This option is the rarest of all. The oxygen saturation of a fish house is always adequately assessed even by novice aquarists. The first thing everyone does is buy an air pump.

The only possible option is an increase in temperature and, as a result, a decrease in oxygen in the water. This can happen at night when plants are rearranged from producing oxygen to absorbing it. To avoid this, do not turn off the compressor overnight.

Aggressive neighbors

Before going to the store for pets, think over to the smallest detail, will several species coexist in one fish house? You should not rely on the competence of the seller, since the main goal for him is to sell as many goods as possible.

A few fundamental rules:

  • Large fish always tend to eat small ones (even in the case of herbivorous species);
  • Many succumb to intraspecific aggression;
  • Some know how to stick to small neighbors, which ultimately turns into death;
  • The strong always eat the weak;
  • Buy only those fish that you are sure of being peaceful.

Unfortunately, it is impossible to establish why the fish are dying. Even experienced breeders can sometimes ask what to do when your fish is dying. Be attentive to the fish, and you will definitely notice a change in behavior and eliminate the cause of anxiety in time. More often, fish in an aquarium die by an oversight, and not by other criteria.

What to do when your fish is dying?

  • Take a closer look at the number of fish in the tank. Count them in the morning and during feeding hours. What is their condition, is the feed taken well? Are there any fish that refuse food? Is it possible for one of the fish to have bloating? If you do not find any fish, check all corners of the aquarium by lifting the lid. Check out the plants, caves, and all the decorations. If after a few days the dead fish did not surface, it is possible that it has suffered from a neighbor in the aquarium, and you will hardly find it. Sometimes fish fall into an unprotected filter and die there. In any case, keep searching until you find the apparent reasons for the disappearance.
  • Fish that have died in the tank must be removed from the tank. Tropical fish species quickly rot due to the elevated water temperature. In such an environment, bacteria multiply rapidly, the water becomes cloudy, an unpleasant odor appears, from which infection of other pets can occur.
  • It is necessary to inspect the dead fish. You must understand why it died in the aquarium. Put on medical gloves. If the body is not completely decomposed, look at the condition of the fins, scales, and the condition of the abdominal cavity. Perhaps there will be wounds on the body or signs that she suffered from unkind neighbors. If the belly is very swollen, the eyes are bulging, the scales are covered with plaque or spots, it means that the pet has suffered from illness or poisoning. Discard gloves after inspection.
  • Check water parameters. Water is often the main cause of poor fish health. Take tests with indicators, and take the necessary measurements. The increased content of ammonia and nitrates, heavy metals in the water leads to the fact that pets die quickly. If the aquarium has a decorative element made of iron, zinc, copper – this is another indicator. Some fish do not tolerate metal well and suddenly die.
  • After the test results, draw conclusions. The test will show two results – either everything is in order in your aquarium, or the water is dirty and contains an excess of toxic substances. In the second case, you need to turn on powerful filtration and replace 25% of the aquarium water with clean and infused water. It is not necessary to drastically change the water parameters, this can harm live fish.
  • But if the water is in good condition, there may be a number of other reasons why the fish died. Sometimes aquarium pets die of hunger, overeating, illness, severe stress, bruises after the attack of other fish, age. If the fish die suddenly, you need to do whatever is necessary to keep others alive. Contact your veterinarian if you have not found an obvious cause of death for your pet.

I hope this article was useful for you and you got an answer for the question of what to do when your fish is dying. Keep your pets well and take good care of them!