Talk about the principle of activated carbon filtration

The adsorption capacity of activated carbon is related to water temperature and water quality. The higher the water temperature, the stronger the adsorption capacity of activated carbon; if the water temperature exceeds 30°C, the adsorption capacity reaches its limit and may gradually decrease. When the water quality is acidic, the adsorption capacity of activated carbon for anionic substances is relatively weak; while in alkaline water, the adsorption capacity of activated carbon for cationic substances is weakened. Therefore, unstable pH values of water quality will also affect the adsorption capacity of activated carbon.

The adsorption principle of activated carbon involves forming a balanced surface concentration layer on its particle surfaces, subsequently adsorbing organic impurities into the carbon particles. Initially, the adsorption effect is highly efficient. Nevertheless, over time, the adsorption capacity of activated carbon gradually weakens, resulting in a decline in the adsorption effect. If the aquarium water is turbid and contains high concentrations of organic matter, the activated carbon will rapidly lose its filtration functionality. Therefore, it is crucial to regularly clean or replace the activated carbon.

The particle size of activated carbon also plays a significant role in its adsorption capacity. Typically, smaller particles offer a larger filtration area. Consequently, powdered activated carbon boasts the largest total surface area and exhibits the most effective adsorption. However, powdered activated carbon can easily disperse into the aquarium with the water flow, making it challenging to control and thus infrequently used. Conversely, granular activated carbon, due to its particle shape, is less prone to flowing away. Organic impurities in the water are less likely to clog the granular activated carbon filter layer. This type of carbon possesses robust adsorption capabilities and is convenient for transportation, carrying, and replacement.

The adsorption capacity of activated carbon correlates directly with the duration of its contact with water: the longer the exposure, the higher the quality of the filtered water. It is important to note that for optimal filtration, the water should exit the filter layer at a slow rate. Additionally, fresh activated carbon must be thoroughly rinsed prior to its initial use to prevent the discharge of ink-black water. Before installing the activated carbon in the filter, it is advisable to place a 2 to 3 cm thick sponge layer both at the bottom and the top to prevent the infiltration of algae and other large particulate impurities. If, after 2 to 3 months of use, the filtration effect diminishes, the activated carbon should be replaced. Regular replacement of both the activated carbon and the sponge layers is recommended to maintain optimal performance.