Water filtration task in an aquarium, its purification from various kinds of particles and suspensions that are found in it, and thus to ensure its suitability for the needs of plants and animals living in the aquarium. Depending on the mode of action, mechanical, chemical and biological filtration is separated.
Mechanical filtration It consists in catching from the water visible contamination to the naked eye, that is, fish waste, plant particles, food debris and other particles. It is based on passing water through dense materials on which dirt particles settle. As filtering substrates mainly sponges or special cotton wool are used here. This type of filtration should be applied in every aquarium and carried out continuously, that is, 24 hours a day. It can be carried out by any kind of filters. Filtering substrates for mechanical filtration should be comparatively often cleaned, since residues deposited on them lead to gradual blockage, as a result of which the effectiveness of the filtration itself is reduced. Filter sponges should simply be rinsed regularly, preferably in dirty water drained from an aquarium. The usual mistake of novice aquarists is washing them directly under the tap (see below for more on this). Filter wool can also be washed, but it is better to just replace it.
The second type of filtering is chemical filtration. It is based on trapping all types of chemical contaminants from water, such as drug residues, heavy metals and other toxins. Partially they are dissolved in tap water – these are the remnants of preparations intended for the preparation of drinking water, others can get into the aquarium together with the dosage of medicines. Since they are harmful to both fish and plants, they should be removed from the water.
Chemical filtration material is activated carbon CARBOMAXPLUS. Being in the filter, he catches from the water and binds various chemicals, neutralizing them. Among experienced aquarists, the prevailing view is that in a healthy, well-functioning and stabilized aquarium, coal should not be used, because in addition to harmful contaminants, it also removes many useful compounds from the water (for example, dissolved vitamins, microelements, humic acids). Unfortunately, this is largely true, and therefore the best solution would be to use filtration with the help of coal not constantly, but only in justified cases. In particular, this filtering is shown in the period of convalescence of fish, for purifying water from the remnants of medicines. However, there are also supporters of the continuous filtration of water through coal (most American aquarists use this method, for example), who argue that removing some useful substances for fish is less dangerous than exposure to harmful substances. This, of course, is a very controversial opinion; However, if we have already decided to constantly use activated carbon in the filters, it should be remembered to eliminate it during the treatment of the fish. Otherwise, the treatment will not bring results. CARBOMAXPLUS activated carbon Available in 1 L packages consisting of two 500 ml each. The special dust removal technology used in its production provides it with the highest purity and eliminates the need for rinsing before being placed in an aquarium. Gradually activated carbon, absorbing the next toxins, loses its absorption properties. Therefore, with constant chemical filtration, charcoal sacks should be changed approximately every 3 weeks.
In addition to activated carbon ZEOMAXPLUS can also be used for chemical filtration of water.. This filler has the form of gravel, consisting of natural zeolite, or rather, of several types of zeolites. These minerals have a specific spatial structure. They consist mainly of oxides of aluminum and silicon, forming a free structure with numerous channels and cavities. This space can be freely filled with water moving inside them, carrying various ions. Due to this, the zeolite has a large sorption capacity: it can absorb and bind various chemical contaminants. When placed in an Fish Tank Filter, it catches harmful nitrogen compounds, heavy metals, and other substances dangerous to fish from water. Unfortunately, over time, its filtering resources are depleted – it needs to be replaced regularly (about once a month).
A new generation of filtering substrates for chemical filtration are fillers containing ion exchange resins: PHOSMAXPRO and NITROMAXPRO. PHOSMAXPRO has the form of functional and easily replaceable bags made of dense non-woven fabric, filled with specially selected ion exchange resin, stabilized with ceramic filler. Due to the large sorption capacity, it effectively purifies water from phosphates, virtually eliminating the possibility of algae reproduction. At the same time it is perfectly safe for fish, shrimp and aquarium plants. NITROMAXPRO is also available in non-woven bags. It is designed to remove from the water dissolved in it nitrogen compounds, which are one of the main causes of poor health of fish and reproduction in the aquarium of burdensome algae. The unique ion exchange resin used in its production has ideal absorption properties. It protects fish from nitrogenous substances harmful to them and allows you to limit the volume and frequency of water changes. Both PHOSMAXPRO and NITROMAXPRO are sold in boxes containing three sachets each. One bag will ensure the purity of water in an aquarium of 200 liters for about 3-4 weeks, after which it should be replaced with a new one.
Phosphates that accumulate in aquarium water can also be removed using PHOSMAXBASIC. It has the form of small gravel, in appearance, resembling miniature ceramic balls. Due to its unique composition, through the implementation of a chemical reaction, it catches from water, binds and absorbs burdensome phosphates. Similar to other filter substrates, AQUAEL is sold in strong boxes containing a filled 1 l bag. It is most convenient to apply it in the same way as, say, activated carbon – pouring it into a special perforated bag (in the absence of such, you can use a regular nylon stocking). It should be placed in the filter, it is best to directly behind a layer of mechanical deposits (sponges or cotton wool) – so that the water entering there is already pre-cleaned. The liner effectively absorbs phosphates from water. At the same time, it is perfectly safe for both aquarium fish and invertebrates, and for plants. It works selectively, without removing beneficial compounds such as trace elements and vitamins from the water. Does not emit any toxic substances. Moreover, it works in the same way as a biological filter, since ideal conditions for the multiplication of nitrifying bacteria are quickly created between its small round particles. Over time, its resources as phosphate absorbent are depleted. For its effectiveness, it is recommended to replace at least once every 4 weeks. The contents of one bag is enough for an aquarium of 200 liters.
PHOSMAXBASIC Works with any type of Fish Tank Filters equipped with containers for bulk substrates. Best of all, it shows itself in combination with canister filters (for example UNIMAX, MINIKANI), as well as with cascade filters and even with some types of internal filters (for example TURBOFILTER). Quickly and effectively solves the problem of excess phosphate in water, thereby preventing undesirable algae reproduction.
The effectiveness of the work of new fillers shows the schedule number 1, 2 and 3:
The third and perhaps most important type of filtration from a fish point of view is biological filtration. It is based on the elimination from the water of nitrogen compounds that accumulate in it unnoticeable to the naked eye. To fully understand this, you need to look at the natural processes occurring in any body of water, that is, also in your aquarium.
Over time, adverse changes occur in aquarium water — as a rule, we call this process “aging” of water. How does this happen? The food that we pour out to the fish contains a large amount of nitrogen (it is part of the proteins necessary for the growth of fish). Fish, eating food, emit nitrogen compounds, mainly in the form of residues of proteins and urea (by calling their own names, fish simply excrement in the water). The main part of these nitrogen compounds is absorbed by plants, but the remains are decomposed by microbes to form ammonia (NH3), which is extremely toxic to fish. Ammonia reacts with water, turning into equally harmful ammonium ions (NH4 +). These ions would instantly poison the water and destroy all the fish, but fortunately in the “mature” well-kept aquarium, as in natural ecosystems, they are immediately oxidized by oxygen bacteria of the genus Nitrosomas to nitrite ions (NO2) (simpler called nitrites), a little less toxic. These bacteria derive energy from this process for their vital functions. From a chemical point of view, it looks like this:
2NH4 ++ 3 O2-> 2NO2- + 4H ++ 2H2O + energy
But that’s not all. The next stage is the oxidation of nitrite ions to much less dangerous nitrate ions (NO3 ¯) (simply called nitrates) – oxygen bacteria of the genus Nistrospira, which also receive energy for their vital functions, are responsible for this process. Simplified it looks like this:
2NO2- + O2-> 2NO3- + energy
In the new, recently equipped aquarium, there are no nitrifying bacteria (and where would they come from there?). They will appear later, getting into it, along with plants or decorative elements from another, already “mature” aquarium. To speed up this process, it was previously recommended to “instill” a new aquarium with water from a healthy, at least a few months old, aquarium. Now instead, special ready-made strains of bacteria are used, which simply need to be added to the water or sprinkled with fillers in Fish Tank Filters. As a result of the activity of the strains of the aforementioned oxygen bacteria, toxic ammonia is replaced by much less dangerous nitrate ions. However, they are also toxic and accumulate in the aquarium. After some time, their number can reach a concentration that threatens the life of the fish. To prevent this, it is necessary to regularly change the water in the aquarium (for details, see the chapter on the care of the aquarium). Together with the water being removed, we get rid of a part of nitrate ions, reducing their concentration in the aquarium. In particular, this is why the regular change of water is so important. But is there really no simpler way, and after some time you will have to run around the apartment with buckets again? Not at all – in fact, nobody changes water in natural reservoirs, and fish and other inhabitants live in them for thousands of years, feeling very good at the same time. All this is due to another group of microbes belonging to anaerobic bacteria. It is already impossible to get energy from nitrate ions in the process of oxidation, but you can use them for breathing. This is what these beneficial bacteria have learned. They live in those zones of the reservoir in which there are disadvantages of molecular oxygen dissolved in water – that is, mainly in the soil layer. They have to draw the necessary oxygen for life from chemical compounds, including nitrate ions. Obtaining oxygen from them, they convert them into the form of molecular nitrogen, which, like gas, evaporates from the aquarium. This is how a complete “withdrawal” of nitrogen compounds from water is carried out. This process is called “denitrification”. From a chemical point of view, it looks like this:
NO3- + 0.5 H2O-> 0.5 N2 + 2.5 O + OH-
All these changes, starting with fish metabolites and right up to nitrogen escaping from the aquarium, are defined as the “nitrogen cycle”. But what does this mean for aquarists in practice? Just that if you want to have a stable aquarium with biological processes proceeding in it, it is necessary to create for certain strains of bacteria the appropriate conditions for their vital activity. This is the phenomenon of biological filtration.
Just like mechanical filtering, this process must be continuous. Its principle is based on the placement in the devices of filtering fillers, creating ideal conditions for the habitat of useful bacteria strains on them, contributing to their decomposition. AQUAEL recommends series BIOCERAMAX substrates.
BIOCERAMAX PRO 600 has the form of cylinders made of porous ceramics, thanks to which its active filtration area reaches 600 sq.m. Bacteria of the genera Nitrosomonas and Nistrospira can settle on this surface, which will ensure the effective oxidation of ammonia to nitrites, and nitrites to nitrates. BIOCERAMAX ULTRAPRO 1200 It has a similar appearance (cylinders), but is made of sintered glass with very small pores. Due to their minimum size, they are placed on the surface in large quantities. As a result, the filtering surface of such a filler reaches 1200 square meters. m
The filler has an even greater active filtration area. BIOCERAMAX ULTRAPRO 1600. It is made of sintered glass in the form of small balls, making it also suitable for small filters (eg for TURBO and UNIFILTER filter containers). Its active filtration area is already 1600 square meters. m. / l! But that’s not all – thanks to the unique shape of the balls, ideal oxygen conditions for the reproduction of the mentioned bacteria, which oxidize ammonia to nitrites, and nitrites to nitrites, reign on the surface, and nitrites prevail inside. As a result, anaerobic bacteria can decompose there, decomposing nitrates to atmospheric nitrogen. Thus, thanks to the use of BIOCERAMAX1600, you can realize the complete nitrogen cycle in the aquarium, providing complete biological filtration.
Attention! Nitrifying bacteria are very sensitive to the effects of chemicals, and therefore it is not recommended to wash filter sponges under tap water (as already mentioned). In addition, a large amount of oxygen is necessary for the vital activity of these bacteria. Therefore, the biological filter must also function continuously – so that a stream of water supplying oxygen passes uninterruptedly through it. A break in the filter for more than several hours, as a rule, leads to its complete exhaustion. All filter models require periodic cleaning and replacement of filter inserts. No less important is the regular cleaning of the rotors of the pumps and their chambers, since contamination by sludge adversely affects the performance of the devices. We should not forget that even the most effective filtering of it will prevent the gradual deterioration of the parameters of aquarium water, since biological filters are not able to remove 100% of the metabolic products of fish from it.