For a super clean aquarium for up to 50 litres you will need Aqua-Flow 50 Filter 150 L/H. It is easy to use and clean with an adjustable flow rate of up to 100 litres/hour. The dual action filter with activated carbon will remove any contaminants chemicals and dyes from the water. The 100% open structure foam provides optimal filtration and bacterial growth area. The 'Easy-clean click system' will ensure easy maintenance - making more time to enjoy your fish. The cartridges are quickly replaced again saving time. The power consumption is low therefore cheap to run and is extremely quiet. It is ideal for coldwater and tropical aquariums. Clean tank - happy healthy fish.