10l biofilter (pressurised) with a 15W U/V combination filter. Typically 40 to 80l/min flow rate and good for smaller ponds up to a maximum of 5,000l stocked at hobbyist levels of fish. Bio filters pond capacity is indicative only – if unsure always buy the next biggest version. You can never ‘over do’ biological filtration, and you never want to ‘under do’ it either. Includes around 130 bio balls.