What are the best aquarium filters for saltwater tanks?

The Reef Octopus Classic 110-INT is an in-sump protein skimmer built from cast acrylic with an Aquatrance 1000s pinwheel pump, venturi air injection, quick-release collection cup and air silencer. It's rated for aquariums up to 130 gal and emphasizes quiet, low-power operation suitable for reef systems.

The AquaClear 110 is a hang-on-back power filter with a multi-stage filtration system (mechanical, chemical, biological), adjustable flow, and a large media basket holding about 300 cu in. It delivers up to 500 gph while using low power (about 14 W), making it efficient and suitable for larger aquariums up to 110 gallons. It ships with foam, activated carbon, and BioMax ceramic media and is designed for both freshwater and saltwater use.

Compact internal protein skimmer designed for BioCube and standard saltwater aquariums up to 32 gallons. Features a self-priming pump, adjustable air flow valve, removable collection cup, and adjustable hanging clips for easy placement and maintenance; suited to nano and small reef setups.

High-capacity canister filter with Smart Pump technology, multi-stage filtration and 5.9 L media capacity; designed for aquariums up to 400 US Gal (1500 L) and suitable for freshwater and saltwater. It offers powerful circulation (563 US GPH) with included mechanical, chemical and biological media and conveniences like auto-purge and utility drain for easy maintenance.

Three-stage HOB filter (mechanical, chemical, biological) with a large bio-wheel for oxygenated biological filtration and Rite-Size C cartridges for mechanical/chemical media; suits freshwater and saltwater setups and offers adjustable intake and reduced-splash covers. It is rated for up to 75 gal and a maximum flow of 350 gph, making it strong for mid-to-large tanks.