
Maintaining excellent water quality is key for all types of saltwater aquarium, but the best saltwater filter can differ depending on the type of tank. Canister filters and hang on backs (HOB) can be great for fish only (FO) or fish only with live rock (FOWLR) marine aquariums.
And we found that the best saltwater filter for these tanks is the Penn Plax Cascade Canister Filter for its large customizable media basket, and adjustable flow at an affordable price.
But if you want to start a large reef tank with coral, the best option is to install a sump with a protein skimmer. That’s why we’ve covered a number of options here including canisters, HOBs, protein skimmers, and media reactors.
So let’s take a look at the options to cover any type of saltwater tank you plan to start!
- Overall Best Canister: Penn Plax Cascade 1000 Canister Filter
- Best For Secondary HOB Filter: Marineland Penguin 350 Power Filter
- Best For Versatile Protein Skimmer: Coralife 220 Super Protein Skimmer
- Best For Premium Canister: Fluval 407 External Canister Filter
- Best For Quietest HOB Filter: AquaClear 110 Power Fish Tank Filter
- Best For Large Saltwater Tank: Fluval FX High-Performance Canister Filter
- Best For Versatile Media Reactor: Two Little Fishies Media Reactor
Best Saltwater Filter Picks Reviewed
Whether you are looking to start a fish only (FO) marine tank, a fish only tank with live rock (FOWLR), or a full reef aquarium with corals, you’ll find a range of filter types here to help choose the best saltwater filter for you.
1. Penn Plax Cascade 1000 Canister Filter
Photo: Amazon.com
- Filter Type: Canister
- Saltwater Tank Type: Fish only (FO), FOWLR
- Dimensions: 11.5 (w) x 10.0 (d) x 17.0 (h) inches
- Flow Rate & Aquarium Capacity: 265 GPH, best for 40 to 50 gallon tanks (other sizes available)
- Filter Media: 3 large media baskets, 3 poly fiber floss pads, 1 coarse bio-sponge, and 1 bag of activated carbon
- Best For: Overall Best Canister
The Penn Plax Cascade 1000 Canister has a powerful flow rate of 265 GPH. But while it’s recommended for tanks up to 100 gallons, we prefer it for a 40 to 50 gallon fish only or FOWLR, as it will cycle your water the 5 to 7 times per hour needed for a saltwater tank.
It has 3 large media baskets which are completely customizable, so you can add specific media like Fluval Clearmax if you are trying to deal with excess phosphates. You could even add filter media for a reef tank if you choose to use it for a smaller reef aquarium.
The intake and output valves can be independently adjusted so you can reduce the flow if you do find it too powerful for your fish. And the valve taps can rotate 360˚ so you can fit it into even the tightest of aquarium cabinets.
You can get the cascade in other sizes, but do make sure the flow rate is enough to cycle your saltwater tank between 5 and 10 times per hour. Overall the Cascade gets plenty of praise from owners for its large, highly-customizable media trays and its affordable price.
2. Marineland Penguin 350 Power Filter
Photo: Chewy.com
- Filter Type: Hang On Back (HOB)
- Saltwater Tank Type: Fish only (FO), FOWLR, reef
- Dimensions: 15.25 (w) x 6.12 (d) x 8.0 (h) inches
- Flow Rate & Aquarium Capacity: 350 GPH, best for 50 to 75 gallon tanks (other sizes available)
- Filter Media: 3 stage filtration consisting of Rite-Size C cartridge (mechanical, chemical) and bio-wheel for wet/ dry biological filtration
- Best For: Secondary HOB Filter
Marineland’s Penguin 350 is a powerful 350 GPH hang on back (HOB) which is fantastic to use as a secondary filter for a larger saltwater tank, including a reef aquarium if you already use a sump as your primary filter system. Other sizes are available too.
It can cycle all the water in a 55 gallon tank around 6.3 times an hour, and 4.6 times an hour for a 75 gallon tank. Not only is this in the range needed for a fish only or FOWLR saltwater tank, but it’s more than enough if you’re using this HOB as a secondary filter.
Mechanical and chemical filtration are provided by Marineland’s Rite Size C cartridge. These are really easy to access and change by simply flipping up the two-piece vented cover, making maintenance incredibly quick.
While some owners have found the Bio-wheel can make some noise as it rotates, in the main most have found it to be quite quiet, and praise this filter for being easy to maintain and a great value price.
3. Coralife 220 Super Protein Skimmer
Photo: Amazon.com
- Filter Type: In-sump or hang on back protein skimmer
- Saltwater Tank Type: Fish only (FO), FOWLR, reef
- Dimensions: 9.0 inch (diameter), 25.0 inch (height)
- Aquarium Capacity: up to 220 gallon tanks (other sizes available)
- Features: Wide needle-wheel aspiration system, wide collection neck with Easy Twist, dual-injection inlets, bubble production diffuser, pump
- Best For: Versatile Protein Skimmer
A good protein skimmer is an excellent additional piece of filtration equipment for removing dissolved organic nutrients, proteins, and tannins from your saltwater tank. And the Coralife Super Protein Skimmer is definitely one of the most versatile.
While most skimmers are either made to sit in your sump or hang off the back of your tank this can do either, meaning you can run it whether you have a sump or not! And while we’ve picked the 220 gallon version here, you can also get it for 65 and 125 gallon tanks.
The Easy Twist collection cup makes it really simple to remove when you need to empty it out, and the bubble production diffuser stops the micro-bubbles produced when the skimmer is running from getting back into your main tank, leaving it clean and clear.
The only real drawback is the instructions could be clearer, which has caused problems for some owners. Although most report this isn’t much of an issue, and overall the feedback is it’s a very versatile skimmer that performs well.
4. Fluval 407 External Canister Filter
Photo: Amazon.com
- Filter Type: Canister
- Saltwater Tank Type: Fish only (FO), FOWLR
- Dimensions: 9.5 (w) x 7.0 (d) x 19.3 (h) inches
- Flow Rate & Aquarium Capacity: 245 GPH, best for 30 to 50 gallon tanks (other sizes available)
- Filter Media: Fully customizable media baskets, media includes 2 x Bio-Foam Max, 2 x BioFoam, BioFoam+, Carbon, and mechanical Quick Clear particles
- Best For: Premium Canister
As a high-quality, premium canister filter for a fish only (FO) or FOWLR marine tank, the Fluval 407 is hard to beat. Whilst Fluval recommends the powerful 245 GPH flow rate for 50 to 100 gallon aquariums, we prefer it for 30 to 50 gallon saltwater tanks.
It will cycle all the water in a 30 gallon aquarium around 8 times an hour and just under 5 times an hour for a 50 gallon tank. This is just in the range needed to keep your saltwater FO or FOWLR tank clean and clear.
Running a canister filter on a saltwater tank needs plenty of maintenance, often around once a week to ensure you don’t get a build-up of nitrates. The AquaStop valves make it easy as you can leave the tubes in the tank without drips, while you disconnect the unit for cleaning.
The Fluval 407 has 4 large filtration chambers which you can customize with your own mechanical, chemical, and biological filter media to get your tank clean and toxin-free. Overall this is a great filter that many owners praise for leaving their water clean within a few hours.
5. AquaClear 110 Power Fish Tank Filter
Photo: Amazon.com
- Filter Type: Hang On Back (HOB)
- Saltwater Tank Type: Fish only (FO), FOWLR, reef
- Dimensions: 17.4 (w) x 12.5 (d) x 11.0 (h) inches
- Flow Rate & Aquarium Capacity: 500 GPH, best for 60 to 90 gallon tanks (other sizes available)
- Filter Media: Fully customizable, comes with AquaClear Foam (for mechanical), Activated Carbon (for chemical) and AquaClear BioMax (for biological filtration)
- Best For: Quietest HOB Filter
The AquaClear hang on back power filter comes in a range of sizes to suit 10 gallon tanks up to 110 gallons, and is one of the quietest aquarium filters available. We’ve chosen the AquaClear 110 here, although we recommend it for saltwater tanks from 60 up to 90 gallons.
At 500 GPH, it will cycle all the water in a 90 gallon tank around 5.5 times an hour which is perfect for a saltwater aquarium, and even great for a reef tank if you are using it as a secondary filter.
It has a large media basket and while it comes with mechanical, chemical, and biological media, there’s also plenty of room to customize with your own. So you can add the best filter media for reef tanks if you own one, to get your aquarium ultra-clean and clear.
As the filter is powerful, we recommend covering the intake with a piece of filter sponge to ensure no delicate fins get damaged. But overall the AquaClear gets great feedback from owners, including those with saltwater tanks, for its quiet and effective filtration.
6. Fluval FX High-Performance Canister Filter
Photo: Amazon.com
- Filter Type: Canister
- Saltwater Tank Type: Fish only (FO), FOWLR
- Dimensions: FX4 15.75 (diameter) x 16.5 (height) inches, (FX6 20.8 inch height)
- Flow Rate & Aquarium Capacity: FX4 700 GPH for up to 250 gallons, FX6 925 GPH for up to 400 gallon tanks
- Filter Media: Fully customizable, FX4 has 4 media basket stages, FX6 has 6 stages
- Best For: Large Saltwater Tank
The Fluval FX series consists of two high-performance canister filters, the FX4, and FX6. While the 700 GPH FX4 is suitable for up to 250 gallon tanks, we prefer to use it in saltwater tanks for up to 100 gallons, and the 925 GPH FX6 in marine tanks for up to 200 gallons.
At these turnover rates, the FX4 will cycle all the water in a 100 gallon tank up to 7 times an hour, while the FX6 will cycle a 200 gallon aquarium up to 4.6 times an hour. These flow rates provide great filtration for a fish only or FOWLR marine tank of these sizes.
With a diameter of 15.75 inches for both models, and a height of 15.6 inches for the FX4 and 20.8 inches for the FX6, these are not small filters, and you’ll need an appropriate aquarium cabinet if you want to hide them away.
But their size does mean their media capacity is fantastic, with 4 media stages in the FX4 and 6 stages in the FX6. So there’s plenty of room to customize with your choice of mechanical, chemical, and biological media to get your marine tank clear and toxin-free.
Overall many owners praise the FX filter for its huge media capacity, powerful filtration, and ability to get their larger tank crystal clear. You can also adjust the intake and output valves if you need to reduce the flow for your fish.
7. Two Little Fishies Media Reactor
Photo: Amazon.com
- Filter Type: Filter media reactor
- Saltwater Tank Type: Fish only (FO), FOWLR, reef
- Dimensions: 3.0 inch (diameter) 11.0 inch (height)
- Aquarium Capacity: one reactor for up to 150 gallon tank
- Features: ½ inch connectors for hoses, 90˚ flexible inlet and outlet fittings, can be used in sump, or hang on back of tank
- Best For: Versatile Media Reactor
Using a media reactor in your saltwater aquarium is a great way of boosting your overall filtration, for example, if you are trying to deal with an outbreak of algae. This Phosban Media Reactor from Two Little Fishies is excellent for this and can be used with many types of media.
As the water is pushed up under pressure from the bottom through the dispersion plate, it gives maximum contact with your media. This ensures the media is the most effective, either to remove toxins or phosphates from your water, depending on the type you use.
It can be placed in your sump, stand in your cabinet, or be hung on your tank, making it very versatile so you can set it up how you want without needing a sump. And the 90˚ rotational fittings make it easy to get the hose positions just right for your setup.
While the fittings are made for ½ inch hoses these are not supplied. You’ll also need a separate submersible pump to use it. But overall many owners give great feedback on this reactor for being simple to use and helping to deal with issues like excess phosphates and nitrates.
Types Of Saltwater Filters And Systems
When looking for the best saltwater filter system for your marine tank there are several types you can choose from, but they all serve slightly different purposes. Let’s look at some of the main types of saltwater filter.

Sumps And Refugiums
If you are looking to start a large saltwater aquarium, particularly a reef tank, the best saltwater filter system is to set up a sump. This is a smaller tank, usually positioned below your aquarium, with the purpose of filtering your water before returning it to the main tank.
A sump tends to be divided into 3 or 4 compartments, often starting with a filter sock attached to the incoming drain pipe to filter out large particulates. It may also include a protein skimmer, suitable filter media, and a heater to re-heat the water before it’s returned to the aquarium.
You can also add a refugium compartment set up with reef mud and lighting, where you can grow macro-algae like chaetomorpha. ‘Chaeto’ is a common, natural method used to absorb phosphates, and this results in less algae in your main tank.
Canister Filters
External canister filters are a good alternative to a sump if you have a fish only (FO) or fish with live rock (FOWLR) aquarium. They draw water out of the aquarium via a siphon hose, pump it through filter media and then return it.
Canister filters come in many sizes suitable for 10 gallon tanks, to over 400 gallons. Fish only saltwater aquariums, and particularly reef tanks, need a higher flow rate than freshwater – around 5 to 10 times per hour turnover. So for a 40 gallon tank look for a canister with at least a 200 to 400 gallon per hour (GPH) flow rate.
Yet even though canisters are powerful, they are one of the quietest aquarium filters too. The other benefit of a canister is they tend to have large media drawers which you can fully customize, so you can use the best filter media for your reef or saltwater tank.
Hang On Back Filters
Hang on backs (HOBs) tend to be the best saltwater filter to use for a smaller marine tank, or as a secondary filter for a larger aquarium. Again, look to use a HOB filter with the correct flow rate for the size of your tank.
HOBs are great for additional filtration as they are quiet and don’t take up much physical space inside as they hang off the back. They are also generally inexpensive in price, and many are highly customizable so you can select the best saltwater media for your tank.
Media Reactors
If you have a specific filtration need, such as dealing with algae outbreaks due to high phosphate levels, a media reactor is the perfect additional filter. It’s usually an acrylic tube to which you add a specific filter media, such as Chemi-Pure Elite for phosphate control.
A separate external pump forces your water through the reactor, and you can set the flow rate depending on the media to get maximum contact and effectiveness, before returning the water to your sump or main tank.
Protein Skimmers
If you plan to start a reef tank, or even for a larger, well-stocked fish only tank, a protein skimmer is another important piece of equipment for the best saltwater filter system. You can get these to sit in your sump or tank, or even protein skimmers that hang off the back.
It works by pumping in water where it’s mixed with air to create fine bubbles. These then disperse into larger bubbles forming into concentrated organic waste which is collected at the top of the skimmer.
How To Choose The Best Saltwater Filter For Your Needs
When choosing the best saltwater filter for your setup there are several factors you’ll need to pay attention to. One of the top considerations is whether you want to start a fish only (FO), FOWLR, or full reef aquarium.

Consider Your Tank Type, Tank Size And Inhabitants
Choosing the best saltwater filter for your tank can be challenging when it comes to marine aquariums, particularly if you are a beginner. There are a number of complex systems you could set up, but the first thing to consider is the type of saltwater tank and size you want to keep.
If you are looking for a small all-in-one saltwater aquarium you’ll often find filters will be built-in, so the only additional filter equipment you may need is a mini protein skimmer. Or for a fish only, or fish with live rock tank, then canister filters are a great choice.
You can also use canister filters for a smaller reef tank containing corals. But if you plan on a larger reef tank then a sump is really the way to go for the best saltwater filter. In this way, you should only invest in a filter system you need based on the type of tank.
Functionality Of Your Filter
Always consider the functionality that your chosen filter offers. For example, the best saltwater filters are often those that have adjustable flow rates. Say you use a canister filter in a small reef tank, depending on the coral they may prefer different flow rates.
Soft corals, for example, generally prefer a lower flow than small polyp stony (SPS) corals. And while you are likely to need to use a powerhead or wavemaker pump to achieve this flow, the ability to control your filter flow return is just as important.
Availability Of Filter Media
Related to functionality is the availability of saltwater filter media, and the flexibility of media you can add. Larger HOBs, and particularly canister filters, are excellent for customization as they often come with large media buckets you can fill with the best saltwater media for your tank.
Price And Quality
On average, the best saltwater filters do tend to be more expensive than freshwater filters, but it very much depends on the setup. One cost-effective approach is to opt for an all-in-one saltwater aquarium that has built-in filtration or partial plumbing.
Some smaller tanks, for example, have fully built-in filtration while you can get larger 40 gallon tanks with a pump, or plumbing for a sump included. Some of the best saltwater filters are canisters and HOBs. But while HOBs are cheaper, they should really be used as a secondary filter unless you have a small saltwater tank.
Whichever filter you go for, remember to check reviews on sites like Amazon. Real feedback from customers is one of the best ways to gauge the quality of the filter you’re buying.
Our Verdict
The best saltwater filter really depends on your setup and primarily whether you intend to keep a fish only (FO), FOWLR, or full reef tank. We found the best saltwater filter for a FO or FOWLR tank to be the Penn Plax Cascade Canister for its great customization at an affordable price.
But if you want to start a full reef tank with corals, a sump with a skimmer is the best saltwater filter system to use. We found the Coralife Super Protein Skimmer to be the most versatile skimmer as it will work in your sump, or you can hang it off the back of your tank.
FAQs
We’ve covered the answers to the top frequently asked questions when it comes to choosing the best saltwater filter for your tank. Take a look at them below.
Are Canisters Or HOBs Better For A Saltwater Tank?
While HOB filters are a great secondary filter for a larger saltwater tank, or good for a small aquarium, overall canister filters are better for a saltwater tank.
What Is The Best Filter For A Reef Tank?
You can use a canister filter with the appropriate flow rate for a smaller size reef tank, but for a large reef tank, the best filter is to set up a sump.
How Often Should I Clean My Saltwater Filter?
A HOB should be checked weekly and any obvious detritus removed. Similarly, if you use a canister filter in a saltwater tank you should look to maintain it every few weeks.
Do I Need Live Rock In My Saltwater Tank?
Live rock is one of the best forms of biological filtration as it naturally comes teeming with beneficial bacteria. But it’s not essential as other biological media can work well too.