cloudy aquarium water

Cloudy aquarium water / 6 causes

Cloudy aquarium water is a challenge faced by many aquarists, regardless of experience. This problem often leads to the death of fish. To prevent death, it is important to understand the reasons for the cloudy water in the aquarium.


Often the water becomes cloudy in a new aquarium since after starting up, a lot of bacteria multiply in the reservoir. This process is natural and inevitable. It is recommended that after starting a new aquarium, put fish in no earlier than on the second day. If it is noticed that the water becomes cloudy, you should wait until the reservoir clears itself, and then start the fish. In the absence of nutrition, bacteria will die, the water balance will be restored.

In this situation, it is forbidden to carry out a water change, since the new fluid will also become cloudy. To speed up the process of normalizing the environment, it is recommended to add water from the old aquarium to the new reservoir, if available.


The water will become cloudy after the first start of the aquarium, if unprepared soil/gravel is placed on the bottom of the container so that the water does not become dirty, it is important to rinse the substrate well to remove small particles and dust. It is necessary to rinse until the water becomes clear and clean during rinsing.


Water quickly becomes cloudy when the food decays. Overfeeding fish leads to an increase in the number of uneaten food residues, the particles sink to the bottom, where they begin to rot. Living in such an environment is dangerous for their life and health. It is recommended to feed the fish so that all food is consumed within 15 minutes.


Another reason why the water has become sharply cloudy can be algae. Certain types of algae have been identified that, when they multiply excessively, lead to clouding of the aquarium environment, the appearance of an unpleasant odor, even after restarting. Excessive lighting and the number of organic elements provoke the active growth of algae, the water becomes opaque with a tint of green, in this case, we can say that the water has become cloudy and bloomed due to microscopic algae.

Water change

An imbalance in an established body of water indicates insufficient and improper care of the internal environment. If the liquid becomes of poor quality and becomes cloudy after changing the water in the aquarium, the reason may be inaccurate filling, as a result of which all suspended particles from the substrate rose up. Do not change more than 1/3 of the fluid more than once a week. After such a change in the environment in a long-neglected reservoir, the biological balance will be disturbed.

Filter or number of fish

If a large number of fish live in the reservoir and the aquarium filter is not working properly, this can cause cloudy water. In fish, such water causes intoxication with decay products, leading to death. Overpopulation with fish is unacceptable, the amount must strictly correspond to the volume of the aquarium. For each living organism, it is necessary to calculate the standard volume of water; on average, 2 liters of water should fall on 1 cm of the fish body. It is recommended to leave a margin, taking into account the growth of pets. Even the highest quality filtration system cannot cope with the problem of consumption of waste products.

Often the reason why the water deteriorates is a failed filter. It can become clogged, ceasing to remove the necessary debris. Such a device must be thoroughly cleaned and it is advisable to change the layer to improve filtering. The cloudy liquid will recover in a few days.

cloudy aquarium

Other reasons

If after cleaning the aquarium the water becomes cloudy again, the reasons may be as follows:

  • poor quality decor elements;
  • poor and irregular care.

All of the above factors, as a result of which the water in the aquarium is cloudy even after replacement, are mechanical reasons and can be easily eliminated.

The materials used in the decor should not be dissolving and with coloring elements. Such elements spoil not only the appearance of the reservoir, they are a mortal danger to living organisms. Often, such water acquires a chemical smell, so if it smells inside the container, you should replace the decorative items of the aquarium. All materials must be safe.

Water color – finding the problem in the aquarium

It is not uncommon for cloudy water in an aquarium to take on color. The shade of the liquid can be different, each color indicates a specific problem inside the reservoir. Shade options:

  • green;
  • Gray;
  • white;
  • brown;
  • unusual color.

The green color of the reservoir indicates the reproduction of algae, microscopic in nature. Turbid green water in an aquarium can occur for several reasons, namely:

  • an excess of direct sunlight of natural or artificial origin;
  • poor filtration;
  • poor quality water.

If, after changing the place of the reservoir to a darker room, the green tint has not changed, you should look for the cause in the filter system. It is recommended to install a quality filter to reduce the number of phosphates and nitrogen. Water should be sent for analysis, if the content of the above elements exceeds the norm, such a liquid must be replaced with the safest one. If the analysis does not show supersaturation with these substances, it is recommended to reduce the fish feeding with dry mixtures. For effective control of microscopic algae, daphnia feeding on them can be placed in the vessel.

Getting rid of

Each owner of an artificial reservoir, as soon as he noticed that the water in the aquarium with fish begins to grow cloudy, tries to decide for himself what to do and how to deal with this phenomenon. Considering all the causes of mechanical turbidity of the water, it is necessary to apply the following methods to eliminate this phenomenon.

Do a good cleaning in the tank:

  • carry out a water change;
  • siphon the bottom;
  • clean all surfaces.

Enhance filtration:

  • clean and wash the filter;
  • install an additional new one or replace both filters with one powerful element.

Cloudiness of water and a green tint of mechanical origin will help to remove the filler from the padding polyester, it is placed in a filter instead of a regular sponge. Explicit changes will be visible after 24 hours.

Another method of removing cloudiness is activated carbon. This absorbent removes impurities in the pond. The charcoal is put in a filter and left inside for 14 days. Lack of coal – is the inability to absorb nitrates and nitrites. The absorbent zeolite will cope with this task. Zeolite is an effective means of dealing with a problem that has arisen. A drug is a group of water aluminosilicates of calcium, sodium, and minerals that are similar in composition and properties.

If the water in the aquarium is contaminated due to biological factors, a number of important steps must be taken to restore the balance:

  • clean the walls of the vessel;
  • clean the bottom and substrate;
  • adjust the amount of feeding;
  • weekly water change in an amount not exceeding the norm.

For the rapid restoration of standard indicators, specialized drugs should be used to suppress harmful organisms and provoke the development of beneficial bacteria.


To restore the biobalance and combat turbidity of a biological nature, the following measures are used:

  • siphoning the substrate;
  • frequent water changes;
  • increased aeration;
  • adding quality water.

These measures will reduce the amount of organic material and free-swimming heterotrophs in the aquarium water. However, just filtering the aquarium water and adding a new portion of the water when changing is not enough. For preventive purposes, chemicals are used.

Care products

All chemicals should be used strictly according to the instructions. Before using it, it is important to make sure that all components in the composition are carried by the fish in the pond. Preparations are necessary for the maximum purification of the liquid for therapeutic and prophylactic purposes.

Tetra medicines convert small particles into large flocs so that impurities can be trapped in the filter. Used for long-term opacification. The tetra preparation in the form of granules is placed inside, if the drug is in liquid form, then it is instilled in the required dose. The positive effect is noticeable after 3 hours; after 12 hours of purification, the water will become perfectly clean. The product is safe and is used before a photo session of an artificial reservoir.

Sera aquaria clear is analogous to tetra. Dregs of a related nature are removed with this tool in a few minutes. Sera has a biological effect and does not contain any active harmful components.
To get rid of nitrates and nitrites in a short time, sera bio nitrivec is used. The tool is designed to launch an artificial reservoir in a short period of time. Bio nitrivec contains a mixture of various detoxifying beneficial bacteria. After its application, the fish can be launched inside a day later, the effect lasts for a long time.


The water in the artificially created home reservoir is alive, purity is ensured by the interaction of all living things inside the vessel. It is important to record the time when turbidity appears in the container. If cloudy green water (or another shade) has arisen in a well-established old aquarium, then important mistakes have been made in the maintenance of the underwater world and immediate action is required to restore balance in the aquarium.