How to put filter material in upper filter fish tank
In fish tank filtration systems, top filtration is a common filtration method. The placement order and type selection of filter materials directly affect water quality and fish health. This article will introduce in detail the placement method of filter media for fish tanks, and provide you with practical suggestions based on the hot topics on the Internet in the past 10 days.
1. The order of placing filter materials in upper filter fish tank

The filter media of the upper filtration system is usually divided into two parts: physical filtration and biological filtration. The following is the recommended placement order:
| Number of layers | Filter media type | Function description |
|---|---|---|
| first floor | filter cotton | Interception of large particle impurities and physical filtration |
| second floor | Biochemical cotton | Cultivate nitrifying bacteria, preliminary biological filtration |
| third floor | Ceramic Ring/Bacteria House | Main biological filter media, hotbed of nitrifying bacteria |
| fourth floor | Activated carbon (optional) | Adsorbs pigments and drug residues, for temporary use |
2. Key points for filter material selection
According to the hot discussions on the Internet in the past 10 days, the following are the filter material purchasing hot spots that aquarists are concerned about:
| Filter media type | Popular brands | price range | User reviews |
|---|---|---|---|
| filter cotton | JBL, white cotton | 10-30 yuan/meter | Easy to clean, needs to be replaced regularly |
| Biochemical cotton | Ehan, A.C. | 20-50 yuan/block | Strong durability and good bacterial culture effect |
| ceramic ring | NO1, mountain tree | 30-100 yuan/liter | High porosity and long service life |
| germ house | MP, Qian Hu | 50-150 yuan/stick | The culture area is large, but it needs to be broken before use. |
3. Operation precautions
1.water flow direction: Ensure that the water flow flows evenly from the first layer of filter cotton to the bottom layer of biological filter material to avoid short circuit.
2.Filter material pretreatment: New filter materials need to be rinsed with fish tank water to remove dust before use (recently, there have been discussions among aquarists about turbid water quality due to lack of cleaning).
3.space utilization: According to the recent hot posts on Fish Tank Bar, the filter material should account for 70%-80% of the volume of the filter box, and the water flow channel should be retained.
4.Maintenance cycle: The filter cotton should be cleaned/replaced every week, and the biological filter material should be simply rinsed every month (pay attention to retaining nitrifying bacteria).
4. Frequently Asked Questions (compilation of recent popular questions and answers)
Q: How long does it take to replace the filter material?
A: The physical filter cotton needs to be replaced regularly (1-3 months), and the biological filter material does not need to be replaced unless it is powdered (recent experimental posts show that high-quality ceramic rings can be used for 3-5 years).
Q: Can different filter materials be mixed?
A: Yes, but pay attention to the matching ratio. Tieba hotly discusses the recommendation of "cotton + porous filter material" combination to avoid using a single filter material entirely.
Q: How to optimize the small upper filter box?
A: Suggestions from popular Douyin videos: ① Use thin biochemical cotton ② Choose small particle filter material ③ Use "zigzag" placement to increase the contact area.
5. Advanced skills (recent sharing from professional forums)
1.Trickle box retrofit: Drilling holes at the bottom of the filter box and transforming it into trickle filtration can increase the amount of dissolved oxygen (recently measured dissolved oxygen increased by 40% at Station B UP).
2.Filter media placed in layers: Place large particle filter materials on the bottom layer and small particles on the upper layer to form gradient filtration (highly praised solution on Zhihu).
3.Seasonal adjustment: In summer, the activated carbon layer can be increased to absorb organic matter, and in winter, the cleaning frequency can be reduced to maintain the stability of the bacterial flora.
By properly placing the filter media, your upper filtration system will achieve the best filtration results. It is recommended to regularly follow the popular discussions on the aquarium forum to obtain the latest filter material usage experience and technical updates.
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