i have 2 fluval 404s on my 75 gallon i was wondering how often i should be taking them apart and rinsing out the media

personally i don't like to clean the filters too often so as you have done I have more filtration than needed. maybe as little as 2 months clean half of one filter then another 2 months do the same with the other. i usually open it and clean the dirtiest parts but only remove half of the total dirt inside. mostly just the foam. I lightly wash the media around 6 months or longer.I never do a total clean of one filter just incase the other packs up on me. Its a matter of having a look and see how much mess is inside I guess. i open mine around 3 or 4 months or so but i have 2 fx5's on a 150g

i never sweep all the crap into my filters but do a vacum once a wk. some people sweep all the crap into there filter, if you are one of these people you may need to clean it out a bit sooner. iu do open and find it fairly clean leave a long gap between cleaning but if you find its very messy open sooner.

Hi Joe

It depends:
If you use activated charcoal you should replace that filter media every month (I do every 3 weeks, and if I don't have a replacement bag, that filter remains without charcoal until I get it), regardless of how you handle other media.

Inspect and, if needed, rinse gently the sponge/fiber and/or bio-balls/ceramics in treated water. If using peat media, remember to place it on top of the activated charcoal (if you use it) but underneath bio-balls/ceramics and sponge/fiber.

Schedule your filter maintenance in alternate periods (e.g. 2 weeks, 1 month), that's the advantage of having multiple filters as you do: you minimize risks of disturbing your cycled tank.

Pepe
Santo Domingo

filtering system plays important role in the aquarium.
it serves as catalyst. it is where good bacteria thrives
and do their purpose. by observing the flow rate of water
through it, you can decides when to do cleaning. as marcus
suggest, clean the dirtiest media and clogged conduit, one at
at time but never pull out the entire media elements. you need
to retain some filter elements for bacteria colonization. i suggest
further not to let the filter hang too long with out running water.
it will kill all good bacteria due to oxygen deprivation.