SHUNTING Bio-cotton Filter High-density Sponge Foam Pool Aquarium Fish Tank Water Filter Cotton (50x50x4cm-25PPI)

• Large size 50 x 50 x 4cm filter pads are available to be cut to fit your filter for any aquarium or pond filter.
• Sponge filters provide mechanical and biological filtration, trap large amounts of waste, and do not clog easily. The size of the pores is measured by the number of pores in the unit area (PPI), the higher the PPI, the more pores in the sponge. It is recommended to use a combination of different size sponges for the best effect.
• Dye-free and safe for aquatic pets. Filter pads are usually used as pre-filters for wet/dry filters, catch basins, and tank filters.
• Regular cleaning. Reusable and durable after cleaning.
• Vacuum sealed and compressed packaging, save space and easy to store, suitable for all types of aquariums. (Unpack first, then restore the size as per the instruction steps, and then it will be ready for use.)

Why do we need to use biochemical filter cotton?Good shading performance, reduce algae growth, moderate pores, high density of nitrifying bacteria, good filterability, stable water quality, reduce fish mortality. Such a combination can achieve the best effect.  Material: biochemical cotton Color: Black. Size: 50 (L) x50 (W) x4 (H) cm Sponge Density:  coarse pores Packing List: 1 x biochemical filter cotton (vacuum sealed). Tips: Replace biological sponge every three months to ensure good filtration effect and growth of nitrifying bacteria.