The biggest canister filter that you find is the FLUVAL FX5. It's rated for up to 400 gallon fish tank. I don't know how quiet it is. You can search an aquarium forums.
Stereo and Fish tanks - noisy need help
I have recently added a 240 gallon freshwater tank in my listening room and it looks incredible. However it is very noisy and has taken away alot of the musical enjoyment. Is there anyone out there that is running a fish tank in their listening room? Is it quiet? What equipment are you using? Any feedback would to helpful!