Hagen Fluval 304 review

About six months ago I picked up a Hagen Fluval 304. It is barely audible running in the cabinet of my 72gal tank. Both the power head and the whisper air pump are much louder than the Fluval. Media replacement is easy enough, and I always take care to clean the impeller every time media is exchanged. The impeller has a cover that has to snap on both ends in order to fully set in place (I often forget this until I hear the unit begin to rattle). So far so good, I also picked up a 204 for a smaller 29gal tank.
The media does get a little pricey, but you can substitute the foam replacement prefilters with pieces cut from a big bag of filter floss.

Some of the reviews on Amazon bag the 404 for wear and tear, but I'm curious if any of these folks cleaned their impellers (as they tend to gunk up over time). Since they also complain of leakage perhaps I'll buy a cheapo container to set the unit in as added insurance down the road.

Random planted tank on the net #2. These guys scatter neutrons for a living and setup a planted tank at the Oak Ridge National Laboratory.