I used one for a while before I set up my sump. My tank is a 55 and I have had no complaints about the 700. Its quiet and can use any type of filter media. My tank was pretty much crystal clear. Not a bad choice. But once again I only used it as a temporary filter, but I think It would work just as good in the long run. (If you are using it in saltwater I would suggest activated carbon in the bottom tray and a phosphate absorber in the top under the floss media.)