ditto on the prev comments about running the Fluval,
i run one onna 75, only thing in it is carbon/Purigen,,and replace the carbon often,,
one thing on the Fluval, watch when you remove the cover over the impeller, when you clean it,,,the lil tabs on the sides tend to wanna break of if you squeeze them to hard,,,use just enuf pressure to release the cover,and remove,,,
same thing on the yellow bracket that holds the impeller shaft,,use the lil metal hook thingie to remove the shaft holder once inna while to keep it freed up in it's slot,(a real bummer to try to remove a stuck one if/when a shaft removal is needed)
also , the impeller cover tends to get brittle over time,and those tabs i was talking about might break , just from running the filter,(been there, seen that) make sure you ,in the future , have a spare handy,or your LFS carries them on a regular basis,,
i've had my 404 since they came out, went thru a "recall" on them over the orig impeller cover(dang thing would stop when ever it wanted to) thinks are ok on the current ones tho,,,
love my Fluval,even tho i gotta send mine back to Hagen for checking out,,,,right now , mine stops for no reason,and having that kind of motor stalled is not a good thing for it,,,,Hagen said ,send it to them ,and they will repair/replace whatever it takes to remedy the problem..(free)just another thumbs up for a manufactor that takes care of , and stands behind thier product,,,,and my 404 is more than a few years old,,,,
sorry for the long post, just wanted to pass along personal input to you,,,