How do sponge filters work? To keep an aquarium clean and maintain the health of the fish, a simple and effective solution often chosen by many is the sponge filter. If you have doubts about how sponge filters work, this article will clarify them for you and introduce the installation method, maintenance tips, and other related knowledge.
👉read more: What is the filtration in chemistry definition?
What is a Sponge Filter?
A sponge filter primarily consists of four components: a sponge, a base, an air pump to provide pressure, and an air tube. The air pump directs water through the sponge, which completes the filtration process.
Although the principle is simple, the filtration effect is excellent. It can remove debris, fish waste, and other large particles. The filtered water, along with particles smaller than the sponge pores (mostly beneficial bacteria), is then returned to the aquarium, gradually cultivating a healthy bacterial ecosystem and stable pH levels, allowing fish to thrive. The gentle pressure applied during the filtration process creates a water flow that does not harm small fry, shrimp, or slow-moving organisms.
The combination mentioned above is the basic setup. Depending on the needs of the aquarium, you can add appropriate sponge filter accessories, such as air stones to reduce noise and stabilize water flow, or choose the appropriate sponge pore size according to the fish species.
How Do Sponge Filters Work?
The operation of a sponge filter begins with water passing through the air pump and being transported into the sponge. Larger impurities in the water are trapped by the sponge’s pores, completing the “filtration” process. The filtered water is then returned to the aquarium with the help of the air pump’s power.
In essence, sponge filters primarily perform physical filtration. However, the porous structure also aids the growth and reproduction of beneficial bacteria, achieving biological filtration.
If you find that the sponge filter is not enough to maintain ideal water quality, you can use it in conjunction with a primary filter or install two different types of sponge filters (with different pore sizes and dimensions) to enhance the filtration effect.
How to Install a Sponge Filter?
Sponge filters usually require self-purchase and installation. Components are provided separately, and it’s up to the buyer to select a suitable location and install them in the aquarium. Here’s a step-by-step guide:
Prepare the Parts and Choose a Location
Select a suitable sponge filter according to the specifications of your aquarium and the type of fish you are raising. After preparing all the components, you can start assembling according to the instructions, combining the sponge and the base.
Connect the Air Tube
Connect the air tube to the air pump’s outlet. Ensure a tight fit to prevent air leaks. Insert the other end into the sponge filter, ensuring a complete connection.
Place the Air Stone
Due to the air pump’s pressure, many bubbles will be generated during the filtration process, and the air tube might not remain tight after prolonged use, increasing the bubble quantity.
To avoid these issues, place an air stone to diffuse and reduce the size of the bubbles, reducing noise and maintaining a stable bubble flow.
Install a Check Valve
If the air pump is positioned below the water level of the aquarium, it is recommended to install a check valve to prevent water from backflowing into the air tube in case of a power outage, which could damage the air pump or motor. To save on the cost of a check valve, you can place the air pump above the water level or aquarium.
Place and Adjust the Sponge Filter
After completing the above steps, the sponge filter is assembled. Now, select an installation location, place it, and adjust it. Most people choose to place the sponge filter in areas with weaker water flow to balance the aquarium’s condition.
However, ensure that the water flow is not too strong to avoid disturbing the fish or aquatic plants. Adjust the flow using the regulator on the air pump.
Finally, make sure the sponge filter is securely fixed, does not sway with the water flow, and that the water circulates well with evenly sized bubbles.
What Impurities Can Sponge Filters Remove?
Despite their simplicity, sponge filters are favored by many fish keepers due to their ability to perform two types of filtration: physical and biological
Physical Filtration (Fish Food, Waste, Particles, etc.)
Physical filtration means blocking particles larger than the pores, such as fish food, fish waste, and other suspended debris. You might think this is just basic debris removal, but the excellence of sponge filters lies in their additional function—biological filtration.
Biological Filtration (Bacteria)
The porous structure of the sponge provides a surface for nitrifying bacteria to attach to, allowing them to reproduce and form a stable and beneficial biofilm.
These nitrifying bacteria help break down ammonia excreted by the fish into less harmful nitrites and nitrates, making the aquarium environment suitable for fish growth. It’s worth mentioning that beneficial bacteria on the sponge take time to cultivate.
If the sponge has an ideal bacterial colony, you can transfer it to a new tank to quickly establish a suitable ecosystem, serving as a backup or emergency tank.
How to Properly Maintain a Sponge Filter?
If the sponge is not maintained for a long time, it may become clogged, reducing the filtration effect or causing the bacterial colony to age. Therefore, regular observation and cleaning are crucial, typically recommended once a month or when the water becomes noticeably dirty.
Maintenance is not difficult: first, remove the sponge from the aquarium. If you are worried about debris falling off, place a plastic bag or fish bag around it before proceeding. To avoid destroying beneficial nitrifying bacteria, do not use tap water or hot water. Instead, gently squeeze and rinse the sponge using water from the aquarium or during a water change, without adding soap, cleaners, or disinfectants, as these chemicals can kill beneficial bacteria and reduce the filtration effect. After fully squeezing out the debris, reinstall the sponge.
If you have multiple sponge filters in the aquarium, stagger their cleaning times to minimize the impact on the bacterial colony.
While regular cleaning can extend the lifespan of a sponge filter, if you notice the sponge becoming noticeably hard, thin, or damaged, it is best to replace it with a new one. You can keep part of the old sponge and use it with the new sponge for a while to speed up the colonization of beneficial bacteria, maintaining continuity in biological filtration.
What Are the Drawbacks of Sponge Filters?
Despite their many advantages, sponge filters also have some drawbacks to consider. In terms of filtration effectiveness, while they can perform physical and biological filtration, they are limited in filtering fine particles and cannot perform chemical filtration.
In terms of maintenance, sponge filters require more frequent cleaning and careful handling to protect the stability of biological filtration. The bacteria cultivation takes time, and the filter’s size and appearance might not be ideal.
However, these drawbacks can be mitigated by choosing the right sponge size and proper use. For instance, installing two or more sponge filters with different pore sizes can improve filtration capacity, and using them as preliminary filters in conjunction with primary filters can enhance overall performance.
Regarding chemical filtration, opinions differ, with some experts suggesting that well-arranged physical and biological filtration can reduce the need for chemical filtration. While bacterial cultivation time cannot be shortened, once a biofilm is established, it can expedite the setup of new tanks. For aesthetic concerns, placing the sponge filter in inconspicuous corners can reduce its visibility.
Overall, the benefits of sponge filters outweigh the drawbacks, explaining their enduring popularity.
Frequently Asked Questions about Sponge Filters
Sponge Filter Recommendations | Getek
The principle of sponge filters is simple, yet they provide excellent filtration results. Because they require only simple components, the quality of sponge filters on the market is generally reliable, with particular attention needed for the sponge’s size and pore size. If you are considering a purchase, you might want to look at products from Getek for superior quality and complete service.
👉read more: How to choose the right chemical filter?
