hi fellow fishkeepers, i was looking for a small filter for an upcoming nano, and i stumbled upon the new fluval internal filter series, the U series. I watched the review on pfk website and decided to purchase one, bought one on ebay for Â£11 quite cheap. i bought the smallest one the fluval U1, its nice and small, with easy openings to clean the sponges, impellor etc. biggest thing i noticed was it was practically silent, compared to the fluval2+ i previously had. Although i wish i had gone for the U2 instead of the U1, because the U2,3,4 have 3 stage filtration and also they have 2 outlet nozzles, which is obviosly better for flow. i highly recommend these filters to anyone, i will be buying another one for my marine very soon.