The JUWEL filter sponge coarse is an essential component of the JUWEL filter system, as it ensures mechanical and biological filtration in the aquarium.

The large surface area and the coarse pore structure ensure a comparatively high and even flow rate of the water.

The bioflow filter sponge is particularly suitable for biological filtration in the aerobic range. The open pores are achieved without the use of chemicals and are therefore free of residues.