Hozelock Ltd Hozelock Bioforce 9000 Filter Foam Current Models You are purchasing a set of 3 compatible replacement foams to fit the hozelock bioforce 9000 and 18000 filter. If you have the bioforce 18000 filter, two sets are required. This set consists of 3 foams. The set is made up of one blue coarse foam, one green medium and one green fine foam. Our replacement foam filters are made from high quality reticulated foam, in the same specification and colour as the hozelock original filters. The fine green foam is slightly smaller than the others as per the original foam specification.