When starting an aquarium, many people focus on choosing fish and plants, forgetting the most important thing — the filtration system. But it is precisely this system that determines the cleanliness and health of your underwater world. The heart of any filter is the fillers, the materials that do the main work of purifying the water.
Different fillers solve different problems. Some trap visible dirt, while others create a home for beneficial bacteria that fight harmful substances. There are also special additives, for example, to soften water or remove medications.
In this article, we will explain in simple and understandable terms what types of fillers there are, what each of them is needed for, and how to combine them correctly. These tips will help you keep your aquarium in perfect condition, ensuring your pets a long and healthy life.
What is a filter media
The filler, or filter element, is the main part of the aquarium filter. It is the filler that performs the task of purifying the water — capturing and filtering out foreign particles and removing organic decomposition products.
Its principle of operation depends on the type and working qualities — there are different cleaning options:
Each method uses its own type of filter media. At the same time, it is often necessary to use all cleaning options at once — mechanical cleaning removes solid particles of various sizes, while biological and chemical cleaning removes organic decomposition products from the water, such as ammonia, nitrites, phosphates, and other toxic components.
The most effective systems are those with several layers of filter media, where each layer performs its own function.
Aquarium filter media is not just filler, but an important part of the water purification system. They help remove dirt, toxins, and harmful substances, and also serve as a home for beneficial bacteria that make the water safe for fish. There are different types: sponges, ceramic rings, carbon, and others — each with its own purpose. The main thing is to choose the one that suits your aquarium and its inhabitants, and not to forget to clean or replace it in time, but not too often, so as not to kill beneficial bacteria.
Types of fillers
Various types of fillers are used in the design of aquarium filters. They can perform specific tasks and separate certain components. Let's take a look at the most effective types:
Activated carbon
This filler can work with maximum efficiency in any type of aquarium, both freshwater and marine. It looks like black granules. The filler chemically purifies the water and acts as a sorbent, extracting and absorbing toxic substances and dyes from the water.
Aquarists classify it as a neutralizer capable of removing phosphates and other harmful elements of organic decomposition. In addition, it absorbs the remains of medications present in the water after treating the inhabitants of the aquarium.
It is important to note that activated carbon cannot absorb ammonia. In addition, it absorbs certain trace elements that are vital for plants.
The service life of one filling is about 4 weeks. It cannot be used continuously — over time, activated carbon becomes saturated and begins to release harmful compounds instead of absorbing them. Therefore, it must be changed periodically.
Sintepon
A filler that performs effective mechanical water purification. It is capable of retaining suspended solids of various sizes. It removes turbidity and dust raised after processing plants and soil.
This material is short-lived — after about a week, it becomes clogged with silt and solid particles and ceases to function. It can be rinsed under running water for reuse. However, this option is not as effective or durable. It is easier to replace the filler.
You can buy special filter elements, or purchase regular synthetic padding and use it — the result will be exactly the same.
Zeolite
A natural material of sedimentary origin. Like activated carbon, it is a neutralizer (sorbent), but with a longer duration of action — up to 1.5 months. At the same time, zeolite is capable of absorbing ammonia, which activated carbon is not capable of.
In addition, the material effectively removes ammonium, heavy metals, fish medications, and dyes. There are many varieties of zeolite — shabazite, lomontite, clinoptilolite, thomsonite, gaylandite, mordenite, and stilbite. All of them have approximately equal capabilities.
The fillers produced under the Hydor brand (owned by the Finnish company PineTech) can be considered a benchmark for quality.
Peat
This filler should be classified as one of the most affordable and inexpensive materials. Thanks to the presence of a large amount of organic components, peat is capable of performing comprehensive water purification.
In addition, the filler has a number of additional properties:
- has a beneficial effect on the roots of aquatic plants, enhancing their growth;
- stabilizes pH in the slightly acidic range;
- sharply reduces the growth of fungi and certain types of bacteria;
- it reduces water hardness.
At the same time, peat has some specific properties. For example, it gives the water a brownish tint, which is not to the liking of all owners. In addition, peat should not be used if the inhabitants of the aquarium have alkaline disease (alkalosis).
The service life of one filling is from 3 to 6 months. The most popular are the two-component products JBL Tormec activ and Sera super peat.
Expanded clay
This artificial filler consists of sintered balls of fired clay. They are airtight but have a porous structure that is favorable for various bacteria to inhabit. In particular, bacteria involved in regulating the nitrogen cycle thrive in the pores of expanded clay.
Expanded clay purchased or collected on the street cannot be placed in the filter immediately. First, it must be prepared — thoroughly washed, then boiled for 15-20 minutes, and then calcined in the oven (temperature regime — 180°).
Expanded clay can be purchased at any hardware store.
Sponge
This material performs mechanical and (partially) biological water purification. Special polyurethane foam (commonly known as foam rubber) is used in its manufacture.
It is important to note that ordinary furniture material is not suitable here; specialized types of filler are required. An example is TetraTec BF (one package contains 2 sponges).
The principle of operation of the filler is based on capturing solid particles. In addition, colonies of bacteria appear in the open pores, converting organic matter into inorganic compounds.
The sponge must be rinsed periodically, and this procedure should take no more than 3 hours.
Bio-balls
These are plastic or ceramic balls with a heavily indented surface to increase its area. These crevices are home to colonies of bacteria that perform biological water purification. However, most aquarists use bioballs as an auxiliary element to ensure more uniform washing of other fillers. This increases the efficiency of purification and extends the service life of the materials.
Seachem Matrix
This filter media is of great interest to aquarists. It is a highly porous material that provides effective biological filtration. It removes nitrogen compounds, ammonia, nitrites, and nitrates.
Eheim Substrat Pro
These are porous ceramic balls with a large surface area—1 liter of filler has an area of 450 m².2. Used in marine and freshwater aquariums.
Seachem Purigen
This is an innovative material produced by American manufacturers. It is a high-quality synthetic adsorbent. Its effectiveness surpasses alternative options. Purigen removes nitrogenous organic decomposition products, normalizing the content of ammonia, nitrites, and nitrates.
In terms of composition, Purigen is an organic resin (not to be confused with ion exchange resin). It is sold in the form of balls or granules, which are highly durable. The material can be restored after regular washing. This is done when the filler becomes cloudy. After washing, the material regains its working qualities. The granules should be stored in water.
Manufacturers
Many companies are involved in the manufacture of fillers.
Among the most popular and reliable manufacturers are the following companies:
AQUAEL (Poland)
The company produces an extensive range of materials, devices, and accessories for aquariums. Among other things, customers are offered a complete set of mechanical, chemical, and biological filter media. You can choose any option — the quality and effectiveness of the products are confirmed by all the necessary certificates and attestations.
Eheim (Germany)
The company develops water filters and filter media. In addition, the company manufactures a wide range of materials and accessories. These include pumps, UV water purifiers, feeders, and other accessories.
Seachem (USA)
The name is derived from the English words “Sea Chemistry.” The company manufactures a wide range of materials and chemicals for marine and freshwater aquariums of various sizes. Filter media is only a small part of the company's product range.
Only the most well-known companies are listed. There are many offers on the market, as there are quite a few specialized companies. Not all of them are widely known, especially those from Southeast Asia. Therefore, it is recommended to use materials from reliable and well-known manufacturers.
Questions and answers
Let's look at the most common questions that users have when choosing a filter media:
Can I use regular activated charcoal from a pharmacy?
Yes, you can. It is recommended to grind the material a little to increase the density of the filling.
Is it worth combining different types of fillers yourself?
If you have sufficient experience and knowledge, you can. The main thing is that the materials do not have a negative effect on each other and do not conflict. However, this option is not recommended for untrained users — there is a high risk of creating unacceptable conditions for fish and plants.
How to choose the right filler?
The choice of the necessary material is made based on the specifics of the aquarium and the characteristics of its inhabitants. The size and type of plants are also taken into account. An aquarium is a complex biological system where all inhabitants are important. Therefore, it is impossible to give unambiguous advice here—certain options must be considered.
Which filler is better?
This is not a valid question. Each filler is designed to solve specific tasks, and it is pointless to compare them with each other. If it is unclear what type of filler is needed in a given case, you can take a combined multi-layer sample that is capable of performing complex cleaning.
Why can't I use regular foam rubber from the store?
There are no direct contraindications. Many aquarists use dishwashing sponges or car sponges. However, it is important to note that the filler must be clean and free of harmful components. Ordinary foam rubber may contain various chemical components that get into the pores during technological processes. Therefore, it is better to use specialized materials.
Choosing filter media is not just a technical detail, but an important step towards creating a healthy environment in your aquarium. As you can see, each material has its own role: some trap dirt, others become home to beneficial bacteria, and still others help adjust water parameters.
Don't try to find a single universal solution. Often, the best results come from a combination of different fillers laid in the right order. Start with simple and proven options, and it's better to experiment with chemical fillers once you have experience and understand the needs of your fish and plants.
Remember that even the best fillers require your attention. Timely but not excessive flushing, monitoring the behavior of the inhabitants, and regular water tests will help the system work effectively. As a result, properly selected and maintained fillers will become a reliable foundation for crystal clear water and a long, happy life for your underwater world.
