The juwel bioflow one is an excellent compact internal filter for aquariums of up to 80 litres in volume. Includes a venturi diffuser and a compartment to add a 50w heater.. Measurements. 10,4 X 22 x 6 cm. Suitable for. Aquariums 25 cm. Filter volume. 0,5 L. Instruction manuals. Bioflow one filter system. Change media filter. Compatibility chart