The best replacement for canister filter is hob.

The best alternatives to canister filter are rated as following:
★★★★★  hob
★★★★★  power filter
★★★★★  sump
★★★  protein skimmer
★★  hang on back
★★  bio wheel
★★  wet/dry filter
★  internal filter
★  wet dry filter
★  sump freshwater
★  refugium
★  sump system
★  undergravel filter
★  wet dry
★  sump tank
  trickle filter
  hang off back filter
  hang on filter

Your alternative for canister filter is not listed? Suggest!
Speaking about canister filter, one probably shouldn't forget about skimmer.

Other search terms related to canister filter and their ratings are:

★★★★★ skimmer
★★★★ sump
★★★★ reef tank
★★★★ protein skimmer
★★★ bio wheel
★★ live rock
surface skimmer
You have in mind a companion for canister filter and it is not yet here? Propose!

Google Trends

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canister filter
power filter