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How many times do you need to change the water in the aquarium

Mature aquarium

After six months, the aquatic habitat reaches maturity. It is now quite difficult to spoil the biological balance achieved in the aquarium. During this period, we also continue to change the water in the aquarium, 20% of the water volume once a month, collecting debris from the ground and cleaning the glass.

Old aquarium

After a year, the aquatic habitat will begin to age. And in order to give the aquarium new youth in the next 2 months, it is necessary to start changing the water in the aquarium more often, also no more than 20% of the water volume, but once every 2 weeks. In this case, it is necessary to thoroughly clean the soil from the organic matter accumulated in it. And after 2 months of such regular flushing, the entire soil should be flushed out, even in the largest aquarium. Thus, we will rejuvenate the aquatic habitat for the whole next year, and then it will be necessary to repeat this operation again.

Thus, you will prevent the degradation of the aquatic environment, without global cleaning of the aquarium, for many years.

Do you know how often to change the water in the aquarium??

Many experienced aquarists argue over how often to change the water in an aquarium, and whether it should be changed at all. From this dispute, only one thing is clear that frequent water changes can cause disease and death of fish.

I found, in my opinion, the clearest and most correct instruction on how often to change the water in the aquarium.

Life in an aquarium, according to the degree of formation of biological balance in it, can be divided into 4 stages: a new aquarium, a young aquarium, a mature aquarium and an old aquarium. And at each of these stages, it is necessary to approach differently to changing the water in the aquarium.

New aquarium

Once the plants are planted in the aquarium and the fish are launched, the aquarist must maintain a stable regime and biological balance in it for many years.

In an aquarium, it is necessary to monitor not so much the state of plants and fish as the state of the entire aquatic habitat. And the main task. maintaining a healthy state not of its individual representatives, but of the entire aquatic environment. And if the aquatic environment is healthy, then the inhabitants will be good in it.

In a new aquarium, as soon as the first fish are launched, the aquatic environment is still extremely unstable and therefore it is not worth interfering with it. In this regard, it is impossible to change the water in the aquarium during the first two months. If in a large aquarium a water change only slows down all the processes of formation, then in a small one it can cause a disaster.

Young aquarium

After two to three months, the aquatic habitat in the aquarium will be a little balanced, but still quite young. During this period, until the complete formation of the aquatic environment, it is necessary to start changing 20% ​​of the water volume once every 2 weeks, or once a month. And if you have the opportunity, it is even better to change 10% of the water volume, but 2 times more often. The inhabitants of the aquarium do not seem to need this, but it is necessary to extend the maturity stage of the aquarium. When draining the water, use the equipment (siphon) to collect debris from the ground, and also clean the glass.

Complete water change

Replacing 20% ​​of the aquarium water will shake the balance of the biological environment, but it will be restored in a maximum of two days. And the larger the aquarium, the faster it recovers.

Replacing half of the water will disrupt the stability of the aquatic environment, while some of the plants and fish may die, but after a couple of weeks the biological environment in the aquarium will be normal.

A complete water change will completely destroy the habitat, and you will have to start the aquarium from the beginning.

For this reason, it is possible to completely change the water in the aquarium only in exceptional cases: violent flowering of water, the continuous clouding of the aquarium, the appearance of fungal mucus or the introduction of dangerous microorganisms.

How much to defend the water for the aquarium

It’s not a secret for anyone that we have not fresh spring water flowing from our taps, but a liquid in which almost the entire periodic table is dissolved. This is easy to see with a simple experiment. Pick up a can of water and see what happens to it for several hours. First, there are gaseous impurities. It would be nice if it was oxygen. Although its overabundance is harmful to the health of fish. Bubbles through the gill slits enter the bloodstream and can provoke thrombosis. But ozone, which in some cities is used to disinfect water, is poisonous. Chlorine and its compounds are also undesirable elements. It is good that gases leave the liquid quickly. an hour is enough. But limescale and rust, washed up from old water pipes, settles on the bottom of the can after 12 hours. Dissolved impurities can be neutralized with special conditioners (eg Sera Toxivec). Here is the answer to the question. It makes no sense to defend water for more than a day. Anything that could precipitate or evaporate has already done it. And then the water just starts to go out, harmful microorganisms start up in it and dust flies.

Mature aquariums

How to change the water in the aquarium during this period and when will there be full biological balance in it? This happens about six months after the installation of the aquarium. over, the larger its volume, the more difficult it is to shake this achieved balance. Therefore, beginners are advised to start large aquariums (100 liters) so that they do not violate the aquatic habitat with their inept actions. During this period of maturity, which lasts up to a year, all we do is change 20 percent of the liquid every month, simultaneously removing debris from the ground and clearing mucus from the glass. However, you need to be careful that the water does not “bloom” (does not turn green). With its regular cleaning, the eyes of the crystal transparency of the aquarium and the agility of the fish that inhabit it will delight for a long time.

Old age: reboot

After a year and a half, the habitat in a closed container begins to degrade. To restore her second youth, it is necessary to change the water every two weeks. Along with regular updating (in the amount of 20% of the total), the following procedure can be practiced from time to time. Experienced aquarists call it “super substitution”. So, your aquarium is filled to the brim with water. We drain 60%, clean the walls and add only 30%. The next day, remove half of the remaining liquid and add the same amount. We repeat this manipulation for the next two days. Finally, refill the tank 30% to the previous level. Thanks to super substitution, the concentration of harmful substances will be reduced by 92%.

How to change the water in an aquarium

Life cycles of aquariums

If you pour water into a container, even if it is settled, you will not yet create a biological sphere that is comfortable for fish. over, being released into such a sterile environment, many inhabitants can die from shock. First you need to place the soil, plant the plants and only after a week launch the first fish. But even at this time it cannot be said that the hydrobiological environment was fully formed. This condition is called by connoisseurs “new aquariums”.

How do you change the water in this type of aquarium? This should be done no earlier than two months after the launch of the inhabitants. A water change can slow down all the processes of establishing a balance, and in small containers it will even cause a catastrophe and mass death of fish. It is allowed to drain 10% of the water in a month and fill to the same volume with fresh.

Water quality

The amount of liquid topped up is not the only indicator that is important for the health of the inhabitants. Quality characteristics. temperature, salinity (for marine fish) and water hardness in the aquarium. are also important. A sharp change in any indicator is a shock to the inhabitants. For tropical fish, the water to be added should be heated to a temperature 1-2 degrees higher than that in the aquarium. The marine biosystem also needs the liquid to have the required ppm. To do this, salts NaCI, MgSO4x7H20, KBr, SrCl2x7H20, MgCl2x6H2O, Na2CO3, KCI, CaCl2, H3BO3, NaF and NaHCO3 are dissolved in distilled or reverse osmosis water for three days.

Aquariums: how to change the water in an aquarium? How much to defend the water for the aquarium

There are three main questions asked by new aquarium buyers. How do I change the water in my aquarium? How often should you do this? And finally, how long does it take to settle the liquid to protect the fish from exposure to harmful substances? In this article we will try to answer these questions.

The main thing to learn for a novice aquarist. it is that he does not raise fish or snails and does not grow algae, but contains a biological environment. This is not a cat or a dog. And not even a turtle. An aquarium is a closed ecosystem, and all efforts should be directed to maintaining its life. And in a healthy environment and inhabitants live well.

New aquariums

How to change the water in the aquarium two or three months after the launch of the first fish? The hydrobiological environment is still quite young. But already on the ground and glass, some deposits can accumulate. Once every two weeks, drain 10% of the liquid using a special siphon. If you do not have this opportunity, it is permissible to change the water once a month, but then it is necessary to update 20% of the container filling. Do not forget to clean the soil and glass during this procedure. Also remove the wilted algae leaves. Even if you put catfish and snails into the aquarium, there is no guarantee that they will fully cope with their task of cleaning bottom sediments and sticking to the walls. The question arises as to how to clean the soil if the water is not completely drained. We will come back to this problem later.

How and how much to change the water in the aquarium?

In this article, we will analyze a fairly simple, but at the same time complex issue regarding changing the water in an aquarium. It is simple because there is no need to change the water in the aquarium. However, there are a lot of nuances and certain specifics that you need to know on this issue. As a rule, information about the change of water in the aquarium is either compressed, or one-sided, or only a certain part is illuminated.

So let’s fix this flaw. We will consider the issue as much as possible and fully.

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For convenience, we will divide the article into the following sections:





Many novice aquarists have different opinions about the need to change their aquarium water. Often on forums or from friends you can hear the phrase: “I don’t change the water at all and…. everything is ok “or” I rarely change, rarely. and everything is ok too. ” Here then, the beginner also has a stupor! How so? Here I furnished the entire balcony with buckets, like a water carrier rushing from the bathroom to the aquarium, and then it turns out that this is a monkey’s work !? Without languishing for a long time, we will answer. do not listen to harmful advice! They mislead you. AQUARIUM WATER MUST BE CHANGED! And that’s why.

In the process of life of all aquatic aquatic organisms (inhabitants), the aquarium itself, or rather the water, becomes polluted. For example, excess food, fish feces, dead leaves of plants and other organic matter. All this dirt turns into the worst poison. ammonia NH4, which is fatal to all life in the aquarium. Further, nitrifying bacteria that are in water, filter and soil decompose ammonia to nitrites NO2 (also a strong poison), then to nitrates NO3 (relatively weak, but also poison), after NO3 it is processed to nitrogen N2. to a gaseous state and comes out of the water.

So, no matter how many colonies of useful nitrifying bacteria in the aquarium, no matter how many live plants in the aquarium that also partially absorb NO3, no matter how powerful the filters are, no matter what starting preparations you use, it is still early or later the above poisons accumulate. Their concentration can be reduced only by water changes.

What happens in the aquarium for those who do not change the water for a long time? Many aquarium fish tend to adapt and live in the most terrible conditions, get used to poisons. However, this function of “survival in any conditions” is not eternal. In fish, irreversible changes occur in the internal organs: mucous membranes and gills. The fish weaken, their immunity decreases. And the “doomsday” comes when there is an outbreak of a bacterial, fungal or invasive attack. not many survive! The aquarium itself reacts to excessive concentrations of nitrogenous compounds with an outbreak of algae and unpleasant odors from the aquarium.

Conclusion, changing the aquarium water is one of the important ways to maintain the biological balance in the aquarium, you cannot do without it. Laziness in this matter is a fatal mistake.!

At the same time, we note that the substitutions need to be done correctly. For example, a complete water change for fresh water. path to imbalance.


There is such a sore in fish, called gas embolism. In a nutshell. this is the ingress of small air bubbles into the vessels and blood of the fish. As a result, there is a blockage of blood vessels. The fish begin to swim sideways, the behavior becomes anxious, fearful. The fins and the whole body begin to tremble convulsively. The movement of the gill covers slows down, and then stops altogether.

Thus, pouring tap water into an aquarium with fish is very risky. Yes, in practice everything can be fine, but this is a game of Russian roulette.

What happens to water if it is defended? And what happens is that small bubbles gradually merge and come out of the water. Air saturation of water is reduced, risks are reduced to zero.

many, need, change, water, aquarium

In addition, it should be noted that in the process of settling the water for the aquarium, the chlorine contained in the tap water is eroded.


Everything is simple here and should not cause any particular difficulties. The water in the aquarium should settle in a container with a wide mouth: a bucket, a basin, an enamel pot. Do not use zinc or aluminum buckets. Sludge containers should not be metal, rusty, or made of toxic substances or paints. Plastic buckets are perhaps the best and easiest option for settling aquarium water.

The longer the water settles, the better. In general, such periods of water settling are wandering on the Internet 1. 14 days.


But this is a really problematic question for owners of large aquariums. How to defend 50 or even 100 liters of water? If this is a new aquarium and the aquarium is being launched for the first time, you can immediately pour tap water into the aquarium, settle there, and at the same time add conditioners to improve water quality.

If water is needed for a change, then in our opinion the only rational option is to purchase construction containers: plastic buckets, barrels for mixing mixtures of 50, 100 liters.

A general recommendation for changes is the use of air conditioners that instantly remove chlorine and heavy metals from tap water, such as, for example, Tetra AquaSafe.

Water Change! How Often? How Much? Why do Them at All?


Almost in all books, on all sites, it is standardly written that you need to change 1/4 of the water from the total volume of the aquarium weekly. This is a generally accepted norm, but not a dogma. Here, please see the statistics of the survey that is being conducted on our forum.

As you can see, everyone changes the water differently and the weekly change of the aquarium water is not a dogma! Why? It’s very simple. everyone has different aquariums, different fish, plants, and so on. For example, there are fish that love “old” water and frequent water changes only annoy them. The abundance of live plants also reduces pollution in the aquarium. In the end, someone has a large aquarium, someone has a small one, someone has large fish, and someone has small.

All this individual specificity of keeping fish excludes the concept of the dogma of the amount and frequency of aquarium water changes. And there is only one advice. you yourself have to adapt and you yourself must come to a conclusion about how often and how much you need to change the water in your aquarium. In this case, you must take into account the volume of the reservoir, the population of the aquarium, the individual characteristics of the fish, the presence or number of plants, the power of the filter, the presence of ion-exchange resins in the filter, and so on. Learn to feel your aquarium.


Finally, we want to draw the attention of novice aquarists to the fact that it is necessary to change the aquarium water after cleaning in the aquarium, and not before.

That is, first we:
– we clean the filter and other equipment;
– we wipe the walls of the aquarium;
– we thin out and cut off the plants;
– siphonym ground;
– we make other manipulations and rearrangements;
– and only then we replace part of the water with fresh one;

Useful video about changing aquarium water

How often to change the water in the aquarium

One of the main questions for novice aquarists is how often to change the water in the aquarium. This question is deservedly very important, because the correct water change in the aquarium helps to ensure the optimal biobalance and maintain the nitrogen cycle. Improper water changes can result in stunted plant growth, fish disease, algae outbreaks and cloudiness.

First, you need to understand 3 main rules:

Never completely change the water in the aquarium without good reason. this will completely destroy the formed microflora in the aquarium and will be tantamount to its complete restart.

Do not allow a long absence of water changes in the aquarium, and even more so completely neglect them. As a result of the nitrogen cycle, ammonia is converted into nitrites, and nitrites then form nitrates, which in an aquarium without living plants are no longer removed from the water, and when a certain concentration is reached, even in a seemingly safe aquarium, fish will begin to get sick and die. Even if you have a sufficient number of live plants in your aquarium, you still cannot be sure that they are consuming all the nitrates from the water.

To understand how often you should change the water in the aquarium, let’s decide on the aquariums themselves, because they differ in their population: fish and vegetable, as well as in age, i.e. time elapsed since the start of the aquarium.

You can conditionally divide aquariums by age into several types:

  • new aquarium (up to 2 months from the date of launch);
  • young aquarium (up to 6 months from the date of launch);
  • mature aquarium (after 6 months).

On the Internet, such a formulation as an old aquarium or old water is often found, in my subjective opinion it is incorrect, since old water may be in an aquarium where no changes were made in full or at all, as a result, a lot of organic matter and nitrates in the water have accumulated in the soil. With correct and regular changes, even after 10 years, the water in your aquarium will remain mature, but not old.

In a new aquarium, as a rule, a weak bio-equilibrium is established, there are no bacteria participating in the nitrogen cycle in the required quantities. Such an aquarium must be handled with extreme caution so that bacterial outbreaks do not occur. Under good conditions in a new aquarium, you should not change the water for 2 months, as this can adversely affect the maturation of beneficial bacteria in it. In order for these good conditions to be preserved, it is necessary to very carefully monitor the food uneaten by the fish, it is better to use live food, to prevent overpopulation. Those. avoid excess organic matter in the water.

If plants grow in your new aquarium, the nutrients for them must be applied in the form of specialized fertilizers, since they are not yet contained in the soil.

In the absence of plants, for example, in cichlids, a good biofilter is needed.

If the conditions in your aquarium are not ideal, for example, the water becomes cloudy, an unpleasant odor appears, etc. then it is necessary to make a water change, because bio-equilibrium has ALREADY been disrupted.

After 2 months, the water in your aquarium will be mature enough to start changing. In a young aquarium, under good conditions, water changes are carried out 10% per week or 20% every 2 weeks.

After 5-6 months from the start, the water in your aquarium is sufficiently mature and the frequency of water changes now depends on your inhabitants. The most frequent water change among aquarists is 25% once a week. With such a change, the water remains sufficiently fresh, nitrates are removed from it. It is this frequency of substitution that some species of fish and plants require for good growth and reproduction. It is not recommended to change water more often and more than 25% per week, so as not to disrupt bio-equilibrium.

If, as a result of certain reasons, you need to replace a large amount of water in the aquarium, then this should be done as follows:

Instead of a one-time replacement of 50% of the volume, we have to change the water 2-3 times a week at 25%, so you will remove the same amount of harmful substances while maintaining beneficial bacteria in the water. Those. when changing water, the rule applies: more often and less than less often and more.

If you are a very busy person and are afraid that you will not be able to cope with the weekly water changes, then you should not worry too much about this, all these numbers are very conditional, many people change water every 3 months and nothing, the fish are alive and well, and the plants bloom and smell. The larger the volume of your aquarium, the smaller the fish population in it, and the more vegetation, the less often you can change that very water, not to the detriment of the health of the fish. After all, not always aquarists need active and enhanced growth of delicate plants and accelerated reproduction of expensive fish species.

All of the above conditions are considered PERFECT and should be guided by them as a beacon that will help you prevent mistakes and the extinction of your fish.

Now, at the end of the article, I will write an example from my own practice: an aquarium of 150 liters, an internal filter, Vallisneria completely expanded throughout the aquarium, 12 adult swordtails in the aquarium, changes were carried out 1 time in 2 months at 30% water. Biobalance is excellent, no one gets sick.

  • the plant vallisneria and the swordfish are very unpretentious.
  • an aquarium completely overgrown with vallisneria works as an excellent biofilter, toxic ammonia and nitrites do not form in the water, only nitrates.
  • a small number of fish (12 pieces) for a fairly large volume of the aquarium (150 liters), there is no overpopulation, the level of nitrates remains normal for 2 months.
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If in the same aquarium there were no vegetation or a good biofilter, and there were 2 times more fish, i.e. overpopulation, I think that after 1-1.5 months without water changes, the fish would all die from ammonia poisoning.

What is it for?

An aquarium is a closed ecosystem with its own biobalance, turbidity or other pollution of the water indicates a violation of the delicate balance. Cloudy or acidic water adversely affects fish, slows down the growth of plants and can lead to disease and even death of the entire ecosystem in the aquarium.

Regular fluid changes are important to maintain a normal nitrogen cycle. A special filter and aerator helps to keep the aquarium water clean, but regular partial changes, additional cleaning of the bottom of the aquarium and removing plaque from the walls are very important conditions for maintaining clean water.

A complete fluid replacement should be carried out only if absolutely necessary, since it is stressful for the inhabitants, and the microclimate after such a restart is built up anew.

In dirty water, fish reproduce poorly, begin to hurt and die. Especially bad water affects expensive fish species, as they are artificially bred and have fragile health.

Optimal timing

Before the first start, all walls in a new aquarium should be rinsed with baking soda and rinsed thoroughly. After installation in the desired place, pour settled tap water, fill with decorative elements and let stand for 2-3 days. If the water remains clean and clear, you can start the fish.

The number of inhabitants, plants and food must be carefully calculated and these data must always be kept at hand until they become a habit. Even the most unpretentious fish should not overpopulate the aquarium. Extra individuals can be sold or given away, as well as plants, because some grow very quickly.

Excess feed negatively affects the digestive system of the fish and contributes to very rapid water turbidity.

You need to change the liquid almost completely no more than once a year for aquariums from 30 to 50 liters, the rest of the time you should only make a partial change of the water that decreases during the cleaning process and due to natural evaporation. Frequent fluid changes disrupt the microclimate in the aquarium and adversely affect its inhabitants.

It is more difficult to maintain cleanliness and biological balance in tanks with a capacity of 20 liters than in large ones, but it is recommended to change the liquid no more than once a week. For beginner aquarists, it is better to buy a container of at least 40 liters in volume to facilitate the care of the ecosystem.

After the first start, it is advisable not to add water for two months in order to establish a biological balance, but it is necessary to clean the bottom and walls regularly.

The first change in a new aquarium should be no more than 10 percent of the total tank volume.

In large aquariums with a capacity of more than 100-200 liters, the task of keeping the ecosystem clean is greatly simplified. A container of such a volume will become dirty for much longer, the bottom can be cleaned once every 3 weeks. Water should be added as needed (you must first let it settle for several days). If a sediment forms in the settled liquid, it is necessary to pour it out not completely so that the settled particles do not get to the fish.

Required inventory

Before carrying out a water change, it should be allowed to settle in a clean glass jar covered with gauze (fixed with an ordinary rubber band around the neck) for 5-7 days. You cannot boil water for fish, since the boiling process kills oxygen and beneficial bacteria (such water is useless and is considered inanimate).

In order to facilitate the procedure for changing or replacing liquid in the aquarium, it is recommended to use the following tools:

  • glass scraper or piece of gauze;
  • a net for fish;
  • scissors for thinning out excess plants (remove the roots from the soil very carefully so as not to damage the plant and not pick up dirt from the bottom);
  • a container for extra fish and plants (it is advisable to use a clean glass jar);
  • a siphon with a pear or an ordinary tube plus a hose for cleaning the soil;
  • bucket for drained dirty liquid.

It is recommended to use a hose with a length of at least 1.5 m. You may also need a filter filler if you plan to clean it.

In the process of changing the water, you can catch the existing fry with a net with a fine mesh, if they are planned to be reared (before that, you need to read when you can plant the young, these times differ for different types of fish).

If there are many plants in the aquarium, a carbon dioxide diffuser can be used. It is convenient to thin out plants with tweezers, but it is not necessary to use it.

In the process of breeding expensive fish breeds, you can use special tests for water, which help to accurately determine the composition of the liquid and ensure the need for a liquid change.

What affects the frequency of replacement?

It is not necessary to change the water in the aquarium very often and it is not difficult to do it.

The opinions of aquarists differ only on one thing: you should change the water completely or leave ¼ of the “old” liquid (after cleaning it) for the best and faster recovery of the microclimate after general cleaning. If the plants or fish are sick, it is necessary to quarantine them in an empty container without decor, rinse everything thoroughly and completely change the water.

Correct water changes will help avoid general cleaning for as long as possible.

If the container has a volume of 60 liters to 100 liters, it is recommended to change the fluid according to the schedule:

  • 1 time in 2-3 weeks, clean the bottom and add water to the usual level;
  • once a month and a half, clean the walls, bottom, rinse the filter filler, clean the decorative elements with a brush (if there is a bloom of brown / green microalgae on them) and renew 1/4 of the liquid in the aquarium;
  • about once a year (or less often), carry out a full general cleaning: place the fish in a separate container with clean water, thoroughly wash the entire aquarium, plants and decorative elements (in this case, ¼ “old” aquarium liquid must be passed through cheesecloth folded in 3 layer and add to a clean aquarium).

A small aqua system is too troublesome, despite the widespread PR of 10-liter tanks, they are hopeless, suitable for keeping 1-2 fish (or growing fry) with the condition of weekly cleaning the bottom and glass, as well as replacing a quarter of the water. The liquid in such aquariums constantly turns sour, blooms and becomes cloudy.

A large aquarium (from 300 liters or more) needs to change the liquid much less often, the main thing is to correctly populate it and arrange it at the first start. If the water becomes quickly and intensively polluted, the cause must be found and eliminated. Among the possible reasons for the rapid turbidity or blooming of water, the following can be distinguished:

  • too small aquarium capacity (10 liters);
  • the aqua system is installed near a window on the sunny side of the house and the water blooms profusely;
  • overcrowding of the aquarium (1 liter of liquid is needed for 1 fish of 3 cm in size, 8-10 liters for a fish of 10 cm);
  • there is no filter in the aquarium or it is faulty;
  • an increased temperature regime provokes acidification of the liquid;
  • the presence of snails, especially large species (despite the generally accepted opinion that snails clean the walls, the amount of their excrement is twice the benefit from cleaning glass);
  • the use of low-quality soil;
  • a thick layer of duckweed on the surface of the water creates a waterlogging effect;
  • overfeeding fish and subsidence of a part of dry or live food to the bottom;
  • feeding the fish with loaf of crumbs or raw scraped meat;
  • poor quality of the water itself (for example, with increased iron or lime);
  • the use of low-quality plant weights;
  • using ordinary river sand as a coating on the bottom (it cannot be cleaned, fish often dig such a bottom and raise the sand).

Ideally, with proper care and maintenance of the aquarium, the water should remain clear and odor-free for several years.

How often should the water in the aquarium be changed and how to do it?

The aquarium is an interior decoration, at the same time humidifies the air in the room and contributes to the emotional relaxation of the owner after a busy day.

Many cafes and shopping centers use beautiful aqua systems to attract visitors, because you can watch the fish for hours. Sometimes aquariums are located in the offices of bosses and directors, because watching the fish, as well as caring for the aquarium, is excellent for reducing stress and improving mood.

Partial water change not only helps to maintain aesthetics and beauty, but also has a beneficial effect on the health of the inhabitants of the aquarium.

Procedure rules

The age of the aquarium affects the frequency of fluid changes. A new aquarium is considered the first 2 months after launch, and it is not recommended to touch the water in it. Young is considered from 2 to 3 months, and fluid change should be no more than 1/5 of the total volume, no more than 1 time in 2 weeks. Mature aquarium. 3 to 6 months, water change. once a week. The aquarium becomes old by the age of two and requires a change of the minimum amount of water that decreases during the cleaning process (no more than 1/6 of the total volume).

It is recommended to carry out a partial water change according to the following algorithm (you do not need to set the fish, it is enough to be careful):

  • clean the walls of the aquarium with a special scraper or piece of gauze from green / brown deposits;
  • remove fallen leaves of plants, excess duckweed;
  • place extra fish, snails and plants in a separate container in order to sell or give them away (or exchange them for food and other necessary things);
  • clean the bottom of the waste products of the inhabitants of the aquarium and food residues using a special tube with a hose;
  • wash your hands thoroughly (you can use a clear, odorless detergent for washing baby dishes for this);
  • remove edge-of-water deposits from the glass with a piece of gauze;
  • if the water is cloudy, drain a quarter of the tank volume through a hose;
  • add settled clean water to the usual level.

A complete water change is rare and takes longer than a partial water change. The rules for a complete water change (such a replacement must be combined with a general cleaning of the aquarium, simple draining / topping up of water will have no effect and after a couple of days the water will become cloudy again):

  • fish and snails must be deposited in a separate container with clean water;
  • the plants should be placed in a basin of water, rinsed thoroughly, the clutches of snails (if they are not needed) and microalgae plaque removed (very carefully, with gauze);
  • all decorative elements should be thoroughly washed with a hard new toothbrush (you can use baking soda, but then rinse thoroughly under running water);
  • all water should be bled out or drained through a hose;
  • the aquarium must be washed with baking soda and rinsed very thoroughly;
  • the soil should be rinsed under a high pressure of water from the shower;
  • fill the aquarium by a third with clean water;
  • equip the bottom, distribute the decor, fix the aerator, filter, heater;
  • plant plants and carefully mask their roots;
  • put a clean deep plate on the bottom and slowly add water to the usual level in a thin stream;
  • in an hour you can launch all the inhabitants back into the aquarium.
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It is not difficult to completely change the water in an aquarium of any capacity, but this should be done only if absolutely necessary. Correct and regular replacement of aquarium water guarantees the maintenance of a healthy microclimate, has a beneficial effect on the health of its inhabitants and gives aesthetic pleasure to its owner.

How to change the water in the aquarium is shown in the next video.

Changing the water in the aquarium: 5 step-by-step steps to change

The aquarium is not only an element of the room decor, but also a home for fish. Novice hobbyists should keep an eye on the tank and its inhabitants. A dirty environment becomes a place for the development of harmful microbes that cause diseases of fish and algae. Changing the water in the aquarium is necessary to maintain biobalance. The frequency of this procedure directly depends on the volume of the reservoir. the larger it is, the less often it should be replaced.

Influence on the inhabitants

Water changes are always stressful for fish and other inhabitants of the reservoir. It is necessary to carry out this operation at least once a week in order to accustom the animals to temporary imbalances.

Neglecting such an important component as changing water can have a detrimental effect on the health of your fish. There have been cases that the inhabitants of the aquarium just got used to the poisons and conditions. After some time, they showed a decline in immunity. The fish became lethargic and inactive. Soon there was a day of an outbreak of fungal or bacterial diseases, during which the creatures died. The decomposition of fish leads to the excessive release of nitrogenous compounds, which provoke intensive growth of algae in the aquarium.

The reaction of plants to a change directly depends on the substances that are contained in the liquid. It is important to consider the percentage of acidity and hardness. It is these indicators that affect the growth of algae.

After a water change, the inhabitants of the reservoirs return to normal life. Performing this regularly will help maintain the concentration of substances in the normal range, as well as create a beautiful aquarium appearance.

Water change rules

I would like to note that it is necessary to change the water in the tank only after cleaning it, otherwise it will be a waste of time and effort. It is worth starting a water change only after several months have passed, since then the desired habitat begins to form in the aquarium.

  • Before starting work, it is required to clean the equipment and decorative elements from food debris and other formations.
  • After that, wipe all the walls of the tank from plaque.
  • It is necessary to remove all food and dead algae from the soil.
  • Plants need to be thinned out. Trim any overgrown ends if necessary.
  • Siphon the soil of the tank.

Owners of large aquariums should not be discouraged. It will be even easier to change the water in such tanks. First you need to prepare the hose. One end of it needs to be lowered into the aquarium, and the other end is brought to the sink. Allow the water to drain. After that, pour the previously settled liquid into the aquarium.

To maintain the biobalance of the reservoir, you need to change the water correctly. It is imperative to monitor the rigidity and try to keep its level the same as that of the liquid in the tank. This is necessary in order not to harm some types of algae, which react painfully to changes in hardness indicators.

It is not recommended to replace more than one fifth of the total volume of water in order not to violate the established biobalance.

Do you need additional filtering

Remnants of food and dead plant parts provoke the development of microbes in aquariums. A white coating forms on the walls of the tank, the water becomes cloudy. You can correct this situation using filtering.

For small aquariums, colonies of beneficial bacteria that break down nitrate and ammonia particles are suitable as a natural filter element. They purify water from impurities and make it transparent.

How often

There are several factors to consider in this matter.

The main aspect when changing water is the so-called population in the reservoir. Some fish prefer old water. Frequent fluid changes lead to illness and other ailments.

Algae also play an important role. From their abundance, the amount and frequency of water changes can vary. Plants are a living filter in the aquarium. The more algae, the less frequent fluid changes occur.

The aquarist must decide for himself how often to change. To do this, you need to know the volume of the tank, the preferences of the inhabitants, the presence of filtering devices.

Why do you need

After arranging the tank with algae and fish, the aquarist must create a stable regime in it to maintain the healthy development of its inhabitants. In the process of life, many elements are released that can have both positive and negative effects. For example, ammonia released from dead plant residues and food particles is detrimental to the inhabitants.


Replacing the water in an aquarium is one of the important components of a healthy ecosystem. Filtration helps to reduce the percentage of harmful substances. They can only be removed with a complete water change.

It is important not to drain all the liquid, but to partially replace it. This is necessary in order to preserve useful elements in the reservoir, which are part of the ecosystem. Before the change, it is required to let the water settle in order to reduce the dissolved oxygen.

How much and why to defend

Fresh water often contains a large amount of impurities and various chemical compounds. During settling, they gradually settle to the bottom, making the liquid suitable for the life of the fish. And also the temperature of the tap water is not suitable for the inhabitants of the aquarium.

The settling time directly depends on the quality of water in a particular region. The more impurities in it, the longer you will have to wait. You can also fill in fresh water, but only when it is not chlorinated. Defending water for the aquarium can be from a day to two weeks. Time should not be neglected. In a few weeks, the liquid becomes completely harmless to the inhabitants of the tanks.

Any dish with a wide neck is suitable for this operation. This is necessary to quickly remove excess oxygen from the fluid. There is no need to select containers made of chemical compounds. A plastic bucket works best. It is necessary to pour water into the dishes and cover with a piece of gauze on top so that foreign objects do not get into it.

Consequences of non-compliance with the frequency

Why fish won’t last long without periodic water changes:

    The aquarium is inevitably gradually contaminated with organic matter (food residues, fauna waste products, dying algae).

All this rots, releasing ammonia, turning into nitrites and nitrates, which are the strongest poisons for fish.
An excess of nitrogen compounds in water provokes an abnormally rapid growth of algae. It becomes uncomfortable for fish to live in such an aquarium. The light does not reach the bottom, the water temperature rises.

Together, these are very favorable conditions for the development of pathogenic microflora. And if we consider that the fish have already weakened their immunity, they will definitely not survive the “epidemic”.

  • Acids are washed out of the pebbles and sand at the bottom of the aquarium. The mineral substances contained in the water participate in the reaction of their decomposition, maintaining the acid-base balance in the norm. With aging, the concentration of minerals in the water decreases, and its overall acidity increases. This also threatens the life of fish.
  • How often, after how many days?

    The intervals between water change procedures depend on the “age” of the ecosystem in the aquarium, a certain stage of its development. There are four of them:

    • New. Having started the ecosystem from scratch, within 3 months the aquarium (with and without a filter) does not need to be “disturbed” at all, allowing the microclimate to form without outside interference.
    • Young (3 months-year). The water is changed once a month (without a filter) or one and a half (with a filter) in a maximum volume of 20-25%. If everything is in order with its quality, 10% is limited.
    • Mature (one to two years old). The water is changed in the same volume, but twice as often. When the fauna and flora are doing well, you can “stretch out” with its replacement for another 7-10 days.
    • Old (2 or more years old). For two months, the water (25-30%) is changed every 2 or 3 weeks (respectively, with and without a filter), combining this with thorough cleaning and washing of the soil. Then, for 8-10 months, they return to the maintenance regimen of a mature aquarium.

    Is it possible to completely abandon these actions?

    You cannot do without changing the water in the aquarium. This is a closed ecosystem, even with powerful and high-quality filters, it is impossible to completely get rid of the almost continuous organic waste, nitrogen compounds.

    Modern alternatives to the change procedure are UV water sterilization, special conditioners and filters. But the experience of aquarists shows that they are only good as an addition to it.

    What liquid to choose and how to prepare it?

    Tap water immediately from the tap is dangerous for fish for two reasons: it contains compounds of chlorine and fluorine that are poisonous for them, as well as oxygen bubbles that provoke gas embolism (in the vast majority of cases, fish die from this disease). But subject to preliminary preparation, it is quite acceptable.

    • rain, because it contains a lot of impurities;
    • filtered (except for the one that passed through a charcoal filter or mechanical cleaning), because if the filtration system provides for saturation with silver ions, antibacterial, remineralizing, ion-exchange cleaning, such water is no longer suitable for fish.

    often than not, aquarists advocate for tap water to make it suitable for fish. The term varies from 2-3 to 12-15 days. It depends on the water quality in a particular region. Don’t rush too much, better wait a little longer.

    Any chemically neutral container is suitable for settling. glass, plastic, enamel. Having poured water, it must be covered so that dust, dirt does not get inside.

    The settled water is poured into the aquarium carefully, trying not to “disturb” the sediment collected at the bottom in the form of whitish or grayish flakes. Before this, a test is necessarily carried out in order to find out the acid-base balance and hardness.

    Alternative preparation methods:

    • boiling;
    • freezing;
    • ultraviolet sterilization;
    • use of special air conditioners.

    However, aquarists still prefer to use them as an auxiliary. They believe that the most effective method is water sedimentation.

    Difference in procedure for small and large containers

    Water from the surface of a small aquarium evaporates faster. Therefore, it needs to be changed more often. This is a disadvantage from an aquarist’s point of view.

    But there is also an advantage. the procedure takes much less time and effort than with a large capacity. The technology itself and the percentage of replaced water, depending on the volume of the aquarium, do not change.

    Factors affecting how many times replacement is required

    How often you need to change the water in the aquarium is influenced by a whole set of factors:

    Step-by-step instruction

    The algorithm of actions varies depending on whether the water is replaced in whole or in part. This is also influenced by its variety. fresh or sea.