Replacement foam set BioPress 4000 INT

For BioPress Set 4000 The heart of a filter is its filter sponges – especially this filter sponge set, which combines the blue and black sponges in a small space. Black filter sponges have extremely fine filtration properties, while the blue ones have coarse filtration properties. This means that, depending on the flow rate of the water, the smallest or only larger particles get caught in the sponges and are thus removed from the pond water. However, they not only perform the classic filtration function, but also provide plenty of living space for the smallest bacteria. This small biological oasis in the filter sponges ensures the conversion of toxins in the pond: in the blue sponges, toxic substances are converted into harmless but algae-stimulating substances (nitrification), which in turn are converted into naturally occurring gases in the black sponges (denitrification).