The Slim Flo filter series by Dymax is a great filter option for nano tanks. Designed to be used for tanks up to 20 gallons, 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. Available in 3 different sizes, these compact filters pair well with Ultum Nature Systems nano tanks!
