Fluval 404 is rated for up to 90 gallons-The new FX-5 is rated for up to 400 gallons. With your fish load, you should probably ensure that your filtration is rated double your tank size and lots of water changes.
with that many fish no way can you do less than once a week water change i run 2- fluval 404 on my 125 i have 2 oscars 1 pleco all about 12or13 inchs and i do water change every week