I currently use all types of Fluval filter for work. If you are looking for a great filter for your freshwater tank, this is what you need. They are well constructed, easy to clean and they can fit lots of media which mean strong nitrogen cycle and a healthy tank. They are a little expensive but it’s nothing if you think at all the advantage. Since Hagen came up with the new 05 series, the Fluval 04 is much cheaper!
Always keep extra motor seal rings on hand, because they do leak. Most leaking problems occur after a cleaning.
One thing I really hate about those filters is the gunk that dislodges from the hoses and end up in my tank when I clean the filter and restart the siphon.
My Fluval still work well after up to 5 years.