The Slim Flo filter series by Dymax is a great filter option for nano tanks. Designed to be used for tanks up to 90L, these filters are beginner friendly and cost-effective. Slim Flo filters from Dymax are as the name states, slim, so they are great for hobbyists with limited space. They have adjustable flow and come with everything needed to properly filter a planted tank. They're also quiet and won't invade your aquascape.
The Dymax Range of Hang On Filters is compact in design and operate very quitely. Whether you have a 30l or 90L tank the Slim Flo Hang On Filter has an adjustable water flow which you can control. The easily replaceable cartridge is an easy, fast and cost effective way to keep your fish tank in great condition for your fish, shrimp and plants.