Perhaps we should first remind you what it really is biofilter. This is a device that allows us to filter the water in the aquarium and at the same time purify it from waste products of fish and other higher organisms. This cleaning involves bacteria, which actually make our filter biological. It is aerobic bacteria that extract nitrates, which are so unfavorable for fish, from aquarium water and, in the process of their own metabolism, convert them into nitrogenous compounds that are harmless to fish. These compounds are subsequently absorbed by plants and then the cycle of transfer of matter and energy is closed. At the same time, our task is to create conditions for the life of bacteria in the biofilter and thereby optimize the operation of the filter-aquarium system.
Without going into theory (quite a lot has been written about biological filtration), we need to create an additional reservoir connected to our aquarium through some water pipes and satisfying the living conditions of bacteria, which will maintain biological balance in our home pond. Actually, it is necessary to create a substrate on which the bacteria will live. And the larger the area of this substrate, the more bacteria can accommodate it. That is why porous materials are used as substrates for biofilters: ceramic elements, expanded clay, various sponges and fibrous materials. Such materials have an incredible surface area due to their own porosity. And that’s all the bacteria need. The more bacteria are placed in the biofilter, the more effective its operation will be.
In fact, there are a great many designs of biofilters, but we will do what you can really do with your own hands. A DIY biofilter will cost much less than a canister filter purchased in a store. In addition, there are many cases where the canister begins to leak and, as a result, in the absence of the owners, almost all the water from the aquarium ends up on the floor. This is because canister filters are located below the water level in the aquarium. Our design will be located above the aquarium, and therefore such troubles are excluded.
To make a biofilter, you will need a pump capable of raising water by about 0.5 meters, hoses for supplying and draining water, a container or plastic box made of reliable plastic, fittings for connecting the hoses to the biofilter body, and a filler for the biofilter.
For an aquarium of 50 - 100 liters, you can make a biofilter from a plastic flowerpot of the appropriate size. The filter circuit is simple: using a pump, water flows from the aquarium into the biofilter (pot), the biofilter container contains a substrate for bacteria, the water washes it and falls down. At the bottom there is a drain and just above an emergency outlet for water.
In a biofilter of this design, several types of substrate can be placed in the form of separate layers. And on the pump it is best to place a sponge that will serve as a pre-filter. You can use a ready-made internal filter, because the task of a biofilter is not to collect large particles, but to purify water from nitrates and other nutrients. But activated sludge is still formed, regardless of whether large debris penetrates the body of the biofilter with water or not. After all, the basis of this sludge is made up of aerobic bacteria and their metabolic products.
The biofilter itself of our design must be located somewhere. If the aquarium is located against the wall, then the easiest way is to use a wall shelf for flowers of the appropriate size. If there is no shelf, you can install a biofilter on the lid of the aquarium. True, you need a fairly strong lid, because the structure itself weighs a couple of kilograms.
To make a biofilter from a plastic box (you can take a tray from an old refrigerator) or a flowerpot (a plastic pot without holes). You will need to drill an inlet hole in the top of its body for water supply. You need to secure a fitting or a plumbing angle in the hole. For sealing, it is better to use silicone gaskets, which can be bought in the same place as plumbing fittings. For reliability, you can also use aquarium silicone.
Next you need to take care of the hole for draining the water. It is best to make it 3–4 cm above the bottom of the container. This will allow you to avoid draining the activated sludge from the biofilter. As in the first case, you need to install the fitting into the hole using reliable seals.
And another hole needs to be made 1 - 1.5 cm above the outlet for emergency overflow of water. We also install a fitting in it.
After the above operations, we attach hoses to the fittings and try to start the entire structure, without filler for now. We look at how the water flows and if there are any leaks.
If everything is fine, you can install the filter in place. Having installed it, we fill it with the filler that we had prepared in advance. The start of biofiltration will not happen immediately. Requires bacterial biomass to accumulate. Only after this the biofilter will start working at full capacity. As a rule, such a biofilter does not require complete rinsing. Although every six months to a year you need to wash it moderately. If possible, without washing away bacterial plaque from the substrate elements.
At the same time, biofiltration solves the problem of accumulation of fish waste products in the aquarium only by half. Bacteria decompose these products to a state in which plants can assimilate them. But here lies the pitfall. If there are a lot of fish and few plants, then an outbreak of microalgae is almost inevitable. But it is possible that there are no plants in the aquarium at all. Either the fish like to feast on plant food, or, according to the aquarist’s idea, there should be a rocky or other landscape that does not include the presence of plants, but here the path lies to a phytofilter, which, in fact, is an improved version of a biofilter.
Filtration of water in an aquarium is an important process, since fish can die from contamination. In the natural environment, feces and other waste from aquatic life are carried away with the flow or dissolved in the huge volume of the reservoir. In conditions of limited space with standing water, it either needs to be changed frequently, which has a bad effect on the microflora of the aquarium and the health of the fish, or a filter must be installed.
What is a biofilter for an aquarium?
There are 3 types of filter devices for aquariums depending on the filter material:
- mechanical– with sponges as a debris trap, their disadvantage is that they need to be washed regularly, otherwise filtration becomes ineffective;
- chemical– using activated carbon and other filtering substances that absorb all unnecessary impurities;
- biological– they are cleaned not with their filler, but with the microorganisms that live in it.
Let us dwell in more detail on the last type of filters. The bio-filler serves as a home for nitrophizing bacteria, which process and neutralize feces and other organic particles in the aquarium. Without this, fish may die from ammonia intoxication.
The larger the volume of the aquarium, the larger the porous surface of the filler should be. Please note that the microorganisms living on it absorb a lot of oxygen, so the oxygen pumping and supply system should not be turned off for more than an hour.
In addition, dead bacteria release poison, so after switching off the sponge must be washed without using running water, since chlorine kills all beneficial microorganisms. For this purpose, water from the aquarium is used and then recycled. For the filter to start working, it will take time for the beneficial bacteria to become active.
Types of biological filters
There are both electric and air filters. The internal biofilter for an aquarium is located inside the aquarium, while the external (remote) one is located underneath it in a stand, on the back of the aquarium, or in the lid above the water level (biofilter built into the aquarium lid).
A dry biofilter for an aquarium is located outside of it, that is, not in water, but in the air and is only irrigated with water. Oxygen is supplied to it from the environment and from water, that is, there is always an oxygen-rich environment inside it, which is important for bacteria. In this case, their accumulation does not occur.
Compared to any natural body of water, the density of fish and plants in aquariums is much higher. Waste products accumulate in them at a rapid pace. An effective solution to this problem is an aquarium biofilter to maintain the correct balance of nitrates and phosphates in a closed aquatic environment with the help of nitrifying bacteria inhabiting it.
If you think that your aquarium does not require any cleaning or intervention in its environment over a long period of time, then you are mistaken, it will quickly turn into a swamp. Many beginners expect to place their fish in a newly purchased one without filters. We immediately have to dispel this illusion and note that only rare craftsmen - lovers of paludariums - can achieve an ideal world inside an aquarium without filtration. In other cases, you have to use a constantly working filter with biofiltration to purify the water. The need for water purification is mainly due to fish waste and uneaten food, as well as dead vegetation inside the tank. When this garbage rots, toxic substances harmful to fish and, in general, to the biobalance of the aquatic environment are released.
Subtleties in application and principle of operation of filters
In application, a biological filter for an aquarium is, in fact, no different from a regular one, except for a special filler, which is populated with a colony of special bacteria to maintain ideal or almost ideal cleanliness in the aquarium. Individual colonies of these microorganisms are capable of eating fish waste products and converting them into less toxic substances (nitrogen cycle).
In the erroneous understanding of many ordinary people, biofilter fillers consist of the same cleaning bacteria. In reality, everything is a little different and there are not microorganisms, but highly porous ceramic balls and rings for them. Any aquatic environment already contains many types of bacterial colonies in minimal quantities. For proper biobalance, you should add a bacterial preparation with certain microorganisms and provoke their growth. Filters maintain the required biobalance in accordance with the type of fish, the abundance of vegetation and other factors in a particular aquatic environment.
As a rule, beginners do not decide to buy a biofilter for an aquarium right away; they wait for the first signs of contamination and then try to solve the problem through mechanical cleaning. The need to use such a product as an external filter with biological purification for an aquarium is mainly due to the desire to have clean water and healthy flora and fauna.
Internal and external structures
Filter designs are of internal or external type with their own disadvantages and advantages. Let's look at the advantages of devices such as an external biofilter for an aquarium. Any experienced aquarium owner can easily name the main advantage of external placement. First of all, this is the low frequency of maintenance of the device in long-term operation. Compared to a product such as an internal biofilter for an aquarium, regular maintenance activities have to be performed much less frequently. Also, the external biofilter for the aquarium does not take up space inside.
For some reason, it so happens that in the literature and on many Internet resources, when the question of bacteria and biofilters in an aquarium is raised, they first of all write about nitrifying bacteria. Yes, these bacteria play a key role in converting toxic ammonia/ammonium into nitrates and this is especially important when starting a new aquarium, in the first month or two. However, these bacteria make up only a small proportion of the microorganisms in the aquarium and the conversion of ammonium to nitrate is just one function of many bacteria. Many aquarists have no idea about most bacteria. This article describes the types and functions of the most important representatives of the microflora of aquatic environments.
What is a biofilter for an aquarium?
In fact, bacteria are a biofilter. It is a mistake to believe that some special filter fillers can perform the function of a biofilter. Until bacteria settle on the surface of the filler, such a filter cannot be called a biofilter. Without bacteria, such filters can only be mechanical, which collect small particles. Moreover, bacteria do not care what surface they settle on. They multiply on any surface that is safe for them. This can be not only the filter filler, but also the soil and even plants. If there are a lot of plants, they form a large surface. Therefore, the entire aquarium is a biofilter.
To understand how the microcosm in an aquarium works, you need to give up the idea that bacteria is a substance that can be added to an aquarium or filter and the more you add it, the more it will be in the aquarium. You need to know two things:
1) Almost all the bacteria that are needed in an aquarium are present in it;
2) Bacteria multiply very quickly from a microscopic colony to millions.
Accordingly, adding bacteria specifically to the aquarium is not always necessary. After all, they are very likely already in it. They are all around us, in the air, in the water, on surfaces. And you need to try very hard not to introduce bacteria into the aquarium. Then the question arises - what is contained in all the preparations that are offered on the aquarium market? As a rule, these preparations contain food for bacteria, some enzymes that stimulate the growth of bacteria and cysts (passive state) of the bacteria themselves. The addition of these drugs creates favorable conditions for the development of bacteria, which, as a rule, are already present in the aquarium. These include the drug AQUAYER Biostarter, which contains food for bacteria in the aquarium and cysts of the bacteria themselves of different types.
Now it is clear that it is important not to place bacteria in an aquarium, but to create conditions for their reproduction and give them food. Nutrition for bacteria is the key to understanding the biobalance in an aquarium. And depending on what kind of nutrition is present in certain zones of the aquarium, the corresponding types of bacteria settle in these zones, each of which performs its own function.
The main types of bacteria in the aquarium and their functions
Up to 60% of bacteria in an aquarium are Actinobacteria. These bacteria decompose organic polymers such as chitin (from invertebrates) and cellulose (from plants) into simpler organic compounds. In an aquarium, actinobacteria form sludge that plants need. Most actinobacteria are aerobes, meaning they require oxygen to function. Therefore, these bacteria settle in areas with good water circulation: upper layers of soil, filter (external or internal), surfaces of plants, glass. The waste products of these bacteria include organic substances responsible for the smell of black soil and what some experienced aquarists call the “smell of a healthy aquarium.”
10-20% of bacteria in an aquarium are Betaproteobacteria, which also includes nitrifying bacteria. Among these bacteria there are aerobes and facultative anaerobes (they can use oxygen, or they can do without it). This type of bacteria plays an important role in the nitrogen cycle, transforming ammonium into nitrite and then into nitrate.
About 10% of bacteria in an aquarium are anaerobes, which can obtain oxygen not from gaseous oxygen, but by breaking down molecules that contain oxygen. In an aquarium, these bacteria live in anaerobic zones, usually the lower layers of the soil, which receive little oxygen. Among these bacteria, the most interesting are Paracoccus denitrificans, because they are responsible for a number of biochemical processes in the aquarium. First of all, these bacteria can reduce the level of nitrates in the aquarium, turning it into nitrogen gas. This process is called denitrification. It is through the process of denitrification that these bacteria obtain oxygen:
The property of these bacteria to reduce the concentration of nitrates is actively used in marine and freshwater aquarium farming. To speed up denitrification in a marine aquarium, nothing more than ordinary vodka can be used as a feed. Bacteria consume ethanol as a carbon source and consume nitrate for anaerobic respiration. At the same time, the level of phosphates also decreases, since bacteria need phosphates as a building material for cells. Without adding anything to a planted aquarium, these bacteria, although slightly, will reduce nitrates and phosphates if conditions are favorable for this. After all, carbohydrates from the cells of dead leaves of aquarium plants can be a source of carbon for them. For freshwater aquariums without plants, such as cichlids and other large fish, AQUAYER NO3 minus can be used to stimulate denitrification. Given a certain diet, these bacteria can even increase carbonate hardness. An important beneficial property of these bacteria is their omnivorous nature. They can consume not only alcohols and carbohydrates as a carbon source, but also many other organic compounds, thereby purifying the water. This property is used in the process of wastewater treatment.
A simple experiment - a “bio-explosion” in an aquarium.
In order to evaluate how bacteria in your aquarium can affect the balance of elements in the aquarium, you can conduct an experiment with sugar. 1 teaspoon of sugar per 100 liters of aquarium water will dramatically increase the population of almost all types of bacteria in the aquarium. Sugar is the easiest carbon source for bacteria to digest. As a result of such an experiment, a number of processes will take place in the aquarium over the course of a week:
1) Aerobic bacteria will reduce the oxygen level and you may notice a lack of oxygen in the fish.
2) Aerobic nitrifiers will reduce the level of ammonium and nitrite, if present in the water.
3) Anaerobic bacteria will reduce nitrate and phosphate levels.
4) The concentration of CO2, as a product of sugar processing by bacteria, will increase slightly.
The next stage is that the bacteria will rapidly increase the population and also rapidly reduce it, because they have already eaten all the sugar. At the same time, the water will be saturated with their decay products (organics), which over time are again processed by bacteria. This method is used to reduce the level of nitrates and phosphates in cichlids. And in order not to upset the balance and not introduce such stress into life in the aquarium, sugar is added in smaller portions - not just 1 teaspoon per week, but spread over 7 days.
How not to harm bacteria in an aquarium and what to do if you do.
What can reduce the bacterial population and upset the balance in the aquarium?
1) Lack of oxygen. Even if it is a planted aquarium, you need to understand that plants do not always produce a lot of oxygen. If they are deprived of food, photosynthesis slows down greatly. As a result, the level of dissolved oxygen in the water can drop sharply. As oxygen levels decrease, the population of aerobic bacteria will decrease. This in turn will lead to the accumulation of those substances that served as food for these bacteria.
The oxygen concentration in a planted aquarium fluctuates throughout the day. At 25 o C, the water is saturated with oxygen up to 8 mg/l, but in aquariums with a large number of plants and their active photosynthesis it can become oversaturated and reach 10 mg/l in the evening. At night, the oxygen concentration drops to 4-5 mg/l even with aeration turned on, since the air contains only 23% oxygen, and oxygen consumption increases at night. A drop in oxygen concentration below 2 mg/l should be avoided. The slightest disturbance on the surface of the water ensures that the oxygen concentration is maintained at a level of at least 4 mg/l during the night.
2) Overdose of CO2 and decrease in pH. Acidic water is an antiseptic; the lower the pH, the higher its antiseptic properties. Not all bacteria like this, so it is better to ensure that the pH does not fall below 6.0.
3) Use of disinfectants. Unfortunately, the drugs that aquarists use to treat fish or fight algae are disinfectants and they greatly disrupt biofiltration in the aquarium. After using them, it is better to carry out a recovery course with the help of biostarters, which have already been mentioned in the article.
Competition between bacteria, algae and plants.
Not only plants and algae are competitors. Bacteria consume the same macro- and microelements as plants and algae. Therefore, in an aquarium with a working biofilter, problems with algae are less likely to occur. Bacteria with plants simply deprive the algae of nutrition. If for some reason the plants have stopped growing, or the bacterial population has been reduced, for example, by the action of disinfectants, then free food for algae appears in the aquarium. In general, if one of these three participants in the biobalance sharply reduces its biomass, the remaining participants may accelerate growth.
The so-called biofilter can speed up the nitrification process. A biofilter can be called any filter that circulates water through a substrate containing bacteria. Circulation is very easy to do - even inexpensive pumps can do this. Bacteria settle on any substrate, be it the walls of the aquarium, plants or soil. The problem is that these bacteria require oxygen for their life, so they can settle in a layer of no more than a few bacteria. Therefore, it is necessary to provide the bacteria with a large surface area so that there are enough of them for the nitrification process. Let us remember that the density of fish in an aquarium is thousands of times greater than in nature, therefore the substrate area for nitrifying bacteria must be very large.
According to calculations by the leader in the production of aquarium equipment, the German company Eheim, for one liter of aquarium water with an average density of fish, about 3 square meters of surface are required to accommodate a sufficient number of nitrifying bacteria. From here it becomes clear why those devices that use cut plastic balls as a substrate for bacteria should not be called a biofilter. The surface area of such balls is very small. To organize sufficient biofiltration, the entire aquarium would have to be filled with such balls.
WHAT CAN A BIOFILTER BE?
As mentioned above, the design of the biofilter can be any. For example, good results can be achieved by placing the entire aquarium soil on a perforated plastic plate with holes smaller than the size of the soil particles. In this case, water must be supplied by a pump under the plate, which in this case is called the false bottom. As a result, we get what is commonly called by the English abbreviation RUGF, that is, a bottom biofilter with reverse water flow.
This method has a number of disadvantages. For example, the effective height of the aquarium is reduced. A number of plants that do not like the flow of roots have to be placed in pots. The required pump power for such a filter must be quite large, otherwise it may simply become clogged with dirt. In total, the pumps should actually ensure pumping of at least 8-10 volumes of the aquarium through the RUGF per hour. This mode of operation is difficult for conventional aquarium pumps and the drop in their performance in this mode of operation is very large. For these purposes, more powerful fountain pumps should be used. In any case, the presence of RUGF does not eliminate the need to also have a filter that will filter out mechanical turbidity.
All problems with biofiltration and water purification from mechanical contaminants are solved by an external filter, which is often called a canister filter, because it is very similar to a canister or bucket with a pump. Such a filter has a multilayer filter material that produces mechanical or biological filtration, respectively. It is quite expensive, but there is no need to skimp on it, otherwise, having suffered with a cheap filter, sooner or later you will have to buy an expensive one.
A good biofilter differs from a bad one by many parameters, which can often only be checked during long-term operation. Our wealth of practical experience allows us to primarily recommend Eheim products. For any size of aquarium and for any population you can find the appropriate biofilter from Eheim. Of the manufacturers of inexpensive canister filters, perhaps only OTTO and RESUN filters can be recommended. Apart from these manufacturers, no one yet produces canister filters worthy of attention.
The formation of a community of nitrifying bacteria is a rather long process. The larger the biofilter substrate area, the longer it lasts. Typically, it takes 2 to 6 months for a biofilter to reach full capacity. You can speed up this process by taking part of the substrate from a mature biofilter or by placing a new biofilter in a successful aquarium with established biofiltration. The exhibition and sale provides these services to its customers free of charge when purchasing a biofilter.
Caring for a biofilter has important specifics. The biofilter compartments, which contain filter material for preliminary purification of water from mechanical turbidity, can be cleaned in any way convenient for the aquarist. As for the substrate with bacteria, its washing must be carried out very carefully. It is best to simply lower the bag with the substrate into the water, lift it out of the water, let it drain on its own, and repeat the procedure several times. If a special sponge is used as a substrate for bacteria, do not wash it clean. It's best to just put it under water, squeeze it, and let it fill with water. Repeat this procedure several times without trying to achieve crystal clear water.
It is possible to organize a biofilter directly inside the aquarium, as is often done in branded aquariums. We believe that this approach is irrational, if only for the reason that this filter on one side is quite large and has to be decorated so that it does not catch the eye. On the other hand, its capabilities are very modest if you plan to keep large fish in the aquarium. In this case, you will still have to buy a high-performance external filter.
To determine the biofilter needed specifically for your aquarium, its configuration and operating rules, please contact our seller. 
Advantages and disadvantages
The advantages of using a biofilter include the following factors:
- The biofilter makes aquarium hygiene much easier, which saves time on maintenance. You no longer have to worry about disposing of the remains of rotting plants, fish excrement, or leftover food.
- The biological filter does not affect chemical processes, occurring in the aquarium after biological equilibrium has been established in it. A biological filter only helps to stabilize this balance and makes the natural processes in the aquarium more intense.
- The cost of a biofilter is not high, besides, you can do it yourself at home.
The disadvantages of a biofilter include a decrease in the effective height of the aquarium, which can negatively affect plants. Also, if you use a sponge as a biofilter, it can become dirty quite quickly.
Fillers for aquarium biological filter
A high-quality filler will promote the rapid proliferation of bacteria in the aquarium. Below we will consider in detail each type of biofilter filler, and also present their advantages and disadvantages.
Foam rubber
This is the most common material for biofilters. Its advantages include the fact that it does not clog as often, unlike padding polyester, as well as a large area for the colonization of bacteria.
In addition, you can buy a foam sponge in almost any store. It should not be changed frequently, it is enough to rinse in a basin with liquid from the reservoir approximately once every two weeks.
Among the disadvantages, it is necessary to highlight the fact that the sponge becomes clogged quite quickly, which can lead to a deterioration in the filtration of water in the aquarium.
Bioceramics
The porous structure of ceramic rings promotes the proliferation and development of beneficial bacteria. There is no need to wash bioceramics, just rinse them occasionally in aquarium liquid. Among the advantages of such a filler, it is worth noting its durability (high-quality ceramics last up to five years). The disadvantages include the relative high cost (good material costs more than five hundred rubles).
Glass
Glass filter media is one of the latest developments in the aquarium industry. Experts believe that this filler is the best today. During the process of heating glass, millions of microscopic holes are formed in it, into which bacteria colonize. The service life of such a biofilter is more than five years. The downside is the high cost.
Special plastic
Special balls are made from plastic with notches on the surface. Among the advantages are durability, as well as the fact that when passing through such a filter, the liquid is actively saturated with oxygen. On the other hand, if low-quality plastic was used to make the filler, this can lead to a disruption in the biological balance in the aquarium.
Sintepon
Synthetic winterizer is used to improve the mechanical cleaning of liquid in the tank. It has a high density, so it traps even the smallest particles of dirt at the entrance. If your filter contains a padding polyester filler, then within a couple of hours after cleaning the aquarium, this filter material is able to retain almost all the dust and turbidity that has risen after cleaning the aquarium soil using a siphon or weeding the grass.
The main disadvantage of padding polyester is that it gets dirty very quickly.. This filler needs to be changed every week, otherwise it will lose all its sorbing properties. Due to its impracticality, synthetic winterizer can be used as an emergency solution when you need to clean the aquarium of mechanical suspensions.
Zeolite
There are serious discussions about the use of zeolite in an aquarium.
Some consider it an “absolute evil”, completely unsuitable for use in an artificial underwater world, while others express the opinion that it is the best filler for a filter.
Among the advantages of this substance are:
- Removing medications from water;
- Use as soil for plants;
- Low cost.
The disadvantage of zeolite as a biological filter is its small pore diameter, which is not enough for the proliferation of beneficial bacteria.
Expanded clay
Not the best choice for filler. It has a small area for bacteria to colonize (25-400 square meters per liter, and for ceramics 600-1400 square meters per liter), and it can also contain phosphates, silicones and heavy metals, which are harmful to the biological balance of the aquarium. The only one the advantage of using this material is its low cost.
WHAT CAN YOU REPLACE A BIOFILTER? OR WHAT IS AQUARIUM PANACEA
Perhaps the price of a biofilter will seem excessive to you. On the other hand, to a picky amateur, the quality of the environment that even the most excellent biofilter provides may seem insufficient, transforming very toxic compounds into not very, but still poisonous ones. How to combine these seemingly mutually exclusive requirements?
Unlike medicine, aquarium farming has its own panacea. Its name is duct! That is, this is such an organization for changing water in an aquarium, when it flows into it in a thin stream around the clock, ensuring a change of 0.3 to 3 volumes of water per day. Smaller numbers are for decorative aquariums, and larger numbers are for nursery aquariums. At the same time, the aquarium water is also constantly poured into the drain and removed into the sewer. The specific implementation of the duct depends on a large number of factors, in any case it is not very complicated, we will not consider it here. For practical questions regarding the implementation of the duct, please contact our consultants. 
If there is a channel, all hydrobionts in your aquarium, be it plants or fish, feel much better. Do not be afraid of the notorious chlorine, supposedly dissolved in large quantities in tap water. In fact, there is such a tiny amount of it that even a one-time replacement of up to 30% of aquarium water with water straight from the tap does not lead to any negative consequences.
Only thanks to the flow it is possible to achieve the best parameters of aquarium water. The quality of water provided by the flow is unattainable by any other means. In addition, the duct will forever save you from problems associated with overheating of the aquarium in the summer.
IS A BIOFILTER ALWAYS NEEDED?
A biofilter is not always necessary. We can say that an amateur either pays money for a biofilter, or installs a duct, or devotes more attention, time and effort to his pets than in the first two cases - the result will be approximately the same.
Loading...