The Slim Flo Filter Series By Dymax Is A Great Filter Option For Nano Tanks.
Dymax SF-240 (240L/H) 
Slim and compact design. 
Silent operation. Adjustable flow rate.
Slim Flo Filters From Dymax Are As The Name States, are Slim and 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.
Color: Clear Smoke