Juwel BioPlus L Coarse Sponge for Bioflow L (6.0). The Juwel BioPlus Coarse Sponge is designed to remove large to medium particles, and its design allows for the proliferation and growth of bacteria thanks to its large surface area. It is recommended to change the BioPlus Coarse Sponge every 3 months to maintain filter efficiency. Suitable for Rio 300/350 and Vision 260 models.