Juwel BioPlus L Standard Fine Sponge for Bioflow L (6.0). The Juwel Fine Sponge Filter Media is designed to remove small to medium sized particles and within its design allows bacteria to flourish and multiply down to its large surface area. It is recommended to change the BioPlus Fine sponge every 3 to 9 months to keep your filter running as efficient and possible. Suitable for JUWEL Rio 300/350 & Vision 260.