Posted: Sun Jul 24, 2011 3:52 am Re: Rena Xp4 or fluval FX5
My FX5 is surprisingly quiet for the amount of water it's constantly pushing. The noise is typically inaudible for the most part, even sleeping 5 feet from it. The filter keeps my 135 gallon, with an average 110 gallons, clean for up to 6 months. Average wattage used by the filter is about 50Watts.
The fx5's larger size also allows for more room to design a filter that really works despite one that is designed to be compact. There is a huge space for biological filtration in the fx5, and that's very important in keeping long times between filter cleans.
-Chris