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A healthy saltwater aquarium requires a clean water, which means you’ll need to choose a filtration system. Biological filtration is a requirement for breaking down ammonia and nitrite, but many people will also want to also add on other types of filters, like mechanical filters that can remove particulate matter from the water before if decomposes.
Read on for the best saltwater filters.
Best Canister Filter: Penn Plax Cascade 700 Canister Filters
Canister filters are among the most popular options for countless aquarists thanks to their inconspicuous appearance and overall roominess—they can generally accommodate more media than power filters. The Penn Plax Cascade Canister Aquarium Filter is our pick for the best canister option for saltwater tanks. It provides all three forms of filtration thanks to its large-capacity, stackable media trays, ensuring your water is clear as can be. It can be primed with the push of a button, and has a flow rate of 350 GPH, making it appropriate for aquariums up to 200 gallons in volume.
Customers rave about the Penn Plax Cascade’s high level of customization—another benefit of its media tray system (it has five baskets, all told). It’s well-made and holds up well over time, making it an all-around great bet for saltwater tank owners looking for a canister-style filter.
Best Skilter Filter: Danner Skilter 250 Power Filter
A cross between a skimmer and a filter, the Skilter 250 Power Filter offers multi-stage filtration along with the benefits of a protein skimmer, which absorbs potentially harmful proteins and toxins by whipping them into a froth before removing them from the tank. It has a 250 GPH flow rate that will work for tanks up to 55 gallons in size and offers user-friendly, self-starting operation. The snap-together cartridge design also allows for easy replacement of the filter media.
The Skilter 250 Power Filter both skims and filters well and is also easy to clean and maintain. While the skimmer function can be a little noisy, some customers have achieved quiet operation by making a few simple modifications to the device.
Best Quiet Filter: Aqua Clear Fish Tank Filter
When you’re focusing on your tank, the last thing you want is to be distracted by a noisy, gurgling filtration system. Fortunately, there are plenty of products out that work quietly without sacrificing the power you want out of a quality filter. The Aqua Clear Power Filter provides efficient mechanical, chemical and biological filtration, but has a unique “waterfall” design that allows it to operate almost silently. With a filtration volume up to seven times larger than many competing products, it’s perfect for 40-70 gallon tanks. It also comes AquaClear Foam, Activated Carbon and BioMax and Cycle Guard, providing constant biological filtration that still preserves beneficial bacteria within your tank.
The Aqua Clear Power Filter is ultra-quiet but still moves plenty of water, and allows for plenty of customization with the filter media. It’s also easy to maintain—it’s not difficult to remove the pump from its housing to clean the impellers.
Best for 20 Gallon Tanks: Tetra Whisper Power Filter for Aquariums
If you’re just testing the waters, so to speak, a smaller saltwater tank may be easier to maintain and keep up than a massive tank. The Tetra Whisper Power Filter is a great entry-level filtration system and works well for small tanks. This external system uses large whisper bio-bag cartridges and offers three filtration systems for your fish. The filter eliminates toxic ammonia and nitrites from your tank’s water while the flow control allows you to manage the strength of the flow to promote better feeding. Best of all, this filter is extremely economical, coming in at less than $20 a pop.
The Whisper Power Filter is reliable and works well to keep tanks clean and healthy. Setup can be tricky, but there are many step-by-step guides to help you through any troubleshooting.
Best for 55 Gallon Tanks: Fluval C Power Filter
Fluval’s C Power Filter goes a few steps beyond other systems, providing five steps of filtration: two mechanical, one chemical and two biological. The result? A healthy tank that’s free of impurities, discoloration, or dangerous ammonia and nitrites. With a 264 GPH flow rate, it’s ideal for mid-sized tanks between 40 and 70 gallons. The filter clips onto your tank for easy installation, and includes a Poly-Foam pad and Bio-Screen—additions that give it the extra filtration steps that set it apart from other filters.
This filter has demonstrated superior performance when compared to competing products, typically resulting in a crystal-clear tank. For the price, it’s considered one of the best filters in the “HOB” (hang on back) category.
Best for 75 Gallon Tanks: hygger Submersible Aquarium Powerhead
If you have a tank that's on the larger side, you’re going to want a filter that can move a high volume of water and provide the power you need to maintain a healthy environment. The Hygger Submersible Aquarium Powerhead has a flow rate of 2000 GPH and features a pair of ball joints, which give you 360 degrees of rotation and ample opportunity to direct the water flow as needed. The high-powered circulation simulates natural ocean currents and is great for marine plants, corals and wildlife—the system can be used in tanks as large as 130 gallons.
Rhe Hygger Submersible Aquarium Powerhead provides the high flow rate they need to keep their large-tank environments healthy, and the creative design allows you to easily direct the flow where you want it. Surprisingly, it also runs almost silently despite its powerful performance.
Best for Large Tanks: Hydor Professional External Canister Filter – Aquarium External Filter
The Hydor Professional External Canister Filter comes in five sizes and can accommodate tanks up to 150 gallons. This canister filter provides all the filtration your tank needs from the biological, mechanical to chemical filtration. It’s an external filter and features a flow rate of 345 GPH. It’s easy to prime and offers telescopic intake tubes for extra water flow. And even though the largest filtration system can work for a 150-gallon tank, it’s so quiet it won’t disturb you at home.
The Hydor Professional External Canister Filter is by far one of the best filtration systems you can buy. It’s incredibly easy to set up and never leaves the job half-done. Though it’s slightly pricier than some filters on our list, it’s well worth the cost if you have a large saltwater tank.
Best Live Filter: Nature's Ocean Bio-Activ Live Aragonite Saltwater Aquarium Sand
Live rocks and sand are excellent biological filtration systems for your saltwater tank. They’re a great alternative to a mechanical system and work well in most settings. The microscopic bacteria and microorganisms that live on the sand make it “live,” and work to consume organic matter in your tank. Nature's Ocean Bio-Activ Live Aragonite Saltwater Aquarium Sand is 100 percent natural sand from the ocean, containing 10 million live marine bacteria. With this sand, you can add fish the same day you set your tank up. The sand works to keep the natural organic balance while reducing waste in your saltwater tank. The live aragonite in the sand helps to maintain a proper pH balance and the sand granules measure between 0.5-1.7 mm.
Nature’s Ocean Sand is low maintenance and doesn’t cloud up the saltwater. It can be added to an active tank, but it’s best to do so slowly. It comes in 10, 20 and 40-pound bags—aim for roughly 1.45 pounds of sand per gallon of water in your tank.