SunSun-China HW-304B 5-Stage External Canister Filter Review

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With a great aquarium comes great responsibility…and the need for a great water filter.

Enter the SunSun Canister Filter.

Aquarium lovers and hobbyists alike know full well the importance of keeping a clean tank: it’s aesthetically pleasing and keeps disease at bay.

The right filter is the difference between a lively aquarium and a dead one. Yet not all filters are created equal. Some are expensive and others don’t clean as thoroughly as you would like.

If you’re looking for a cost-friendly, quality water filter, then look no further than the SunSun HW-304B 5-Stage External Canister.

Made for tanks of up to 150 gallons, this filter siphons and cleans water with ease. It can handle large volumes of water, its filtration system ensures a deep clean, and it comes with a UV light to kill other forms of harmful bacteria.

Equipped with plenty of features that will satisfy even the most discerning of aquarium owners, the HW-304B stacks up against its competition.

But where does it fall short?

Let’s get right into it…

SunSun China HW-304B 5-Stage External Canister: The Details


  • Weight: 14 lbs
  • Dimensions: 11 x 11 inches, 17 inches high
  • Filter Capacity: 150 gallons
  • Filter Capacity: 525 GPH/ 2000L per hour
  • Media Stages: Biological, mechanical, and chemical
  • Self-priming or Standard: Self-priming
  • Warranty: Contact company for details

sunsun china hw-304b canister filter review

SunSun Canister Filter Features

The HW-304B exhibits a number of features that make it a powerful filter to consider for your home aquarium.

Water Cycling

As previously stated, this device can filter 525 GPH per hour, which is astounding — especially at this low price point.

There won’t be any concern for the cleanliness of your tank; the water will be continuously cycled and cleaned throughout the day. It will remain crystal clear as the day you first assembled your aquarium.

Five Stage Filtration

If you’re worried about how thorough of a clean this device is capable of, then it’s time to put your mind at ease.

The SunSun canister filter boasts three different filtration types that effectively purges the water of harmful chemicals and compounds.

The chemical stage removes undissolved substances within the water (such as carbon), the mechanical stage destroys harmful algae and bacteria, and the biological stage converts waste into nitrites, then nitrates.

You can be confident knowing that your reef won’t wither away or your fish won’t fall ill because a filter isn’t doing its job.

Stackable Media Trays

Another feature of the HW-304B is that it has four trays that allow for the stacking of other media for extra filtration.

This media can be used for chemical, mechanical, or biological filtration to add that extra “oomph” to your device.

The media included are activated carbons, bio balls, and ceramic rings.

UV Sterilizer

What sets the SunSun HW-304B apart from the rest is the nine-watt UV sterilizer, a feature built for killing pathogens, algae, and bacteria that can harm the life within the tank.

It aids in reducing the likelihood that your fish and reef will succumb to disease, a nightmare for even the most seasoned of aquarium enthusiasts.

This feature is what makes this filter unique, as there aren’t many out there that have UV sterilizers.

Self-Priming Pump

We know we’re not the only ones that hate having to manually siphon your water through the filter — thankfully you won’t have to with the SunSun’s self-priming pump.

The fact that it’s self priming essentially means that it will continually pump water through the filter, ensuring crystal clear water all the time.

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SunSun Canister Filter Review

The Positives

Now that we’re done with the features of the SunSun external canister filter, let’s take a look at the positive aspects of the device.

Low Cost

For a device that works so well, you would assume it would cost an arm and a leg — but it’s far from it!

The fact that it can service up to a 150 gallon aquarium is only an additional bonus, allowing you to keep your accessories on the budget side even if you’re well ensconced in your hobby.

Anyone with a large aquarium can rest easy knowing that this filter certainly won’t be the priciest of their expenses – and owning a large aquarium can definitely be pricey.

More Advanced Than its Competitors

Leading on from the previous point, it’s immediately clear where the SunSun canister filter stands out from its similarly priced peers: the UV sterilizer.

We’re not aware of any other filter offering this awesome feature at this price point, which means that it’s a major selling point.

The UV sterilizer is expertly equipped to kill bacteria and algae spores in your aquarium, keeping it and your water clean, ensuring the longevity and health of your fish.

It Runs Quietly

Filters are known for being loud and annoying, but this filter is so quiet that you won’t know it’s working!

Though this may not be a concern for most, for some, the noise can be a crucial factor in what filter they want to buy.

This filter won’t keep you up at night or irritate guests who want to marvel at your aquatic display.

Especially useful for fish keepers living in apartments!

Easy Cleaning and Maintenance

Cleaning filters can be a hassle, and when they aren’t cleaned properly, their performance can be affected.

The purpose of a filter is to save you time and to clean better than you ever could.

The SunSun China External HW-304B Filter is easy to clean and contains a self-priming pump that won’t need manual siphoning. There’s no need to get your hands dirty with the gunk and grime that filters accumulate – the process is simple and easy to do.


The device itself is maneuverable to a point where it’s not remotely a hassle to get it from location A to location B.

Some filters can be heavy or clunky, becoming a nightmare to move around. Maybe you are moving and you need to take everything with you, or maybe you want to rearrange your aquarium to better enhance your living space.

Whatever the reason, the HW-304B is only around 14 pounds, so when the time comes, it can go wherever you want your aquarium to go.

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Comes with Everything You Need to Get Started

One of the biggest complaints we hear about so many of these expensive aquarium accessories is the fact that you’re required to buy a load of extras on top of the initial purchase to get them working properly.

But not only is this a fully functioning standalone model, it also comes with some filtration media to get you started too:

  • Ceramic rings
  • Active carbon
  • Biochemical cotton
  • Bio balls

Of course, you’ll have to top up this with extra media as and when you need it, but that’s perfectly acceptable.

The Negatives

You can’t have the good without the bad, and this product is no exception. Here are a few things to know when considering this filter.


The directions that come with the device can be confusing, which can impede the assembly process.

Let’s address the elephant in the room here: the SunSun HW-304B is a Chinese product. The item itself works very well — the accompanying instructions… not so much!

As happy as you are to finally find the filter you need, it’s understandable that you don’t want to scratch your head trying to figure out how to put it together.

Thankfully there are YouTube videos that show how to assemble the filter for those who can’t make heads or tails of the instructions.

Check this one out for starters:

Tray Assembly

This canister filter is generally very well made, but there is one design flaw that we’ve spotted.

The four trays within the device don’t seal all the way, so a little bit of water can seep through as the rest of the water is being filtered.

We didn’t find this to be a dealbreaker as the amount isn’t enough to cause any issues down the road, but it is indicative of a less than perfect construction.

Sterilizer Heat

Though the nine-watt UV sterilizer is an added bonus to the filter, there have been instances where, if left on for too long, it might damage or even melt the plastic of the tank.


Though this may sound alarming, the instances in which this has happened had led to minimal damage at the worst. It’s a small issue easily remedied by making sure to turn off the light after a period of time (like when you go to work or when you go to sleep). Just make sure that you’re paying attention!

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Overall Verdict

We highly recommend the SunSun canister filter to any aquarium lover because of its generally excellent cleaning capacity and very reasonable pricing. Tank water will look clear as day and free from dirt and chemicals.

It’s not perfect — and you shouldn’t expect perfection at this price point — but it’s certainly leaps and bounds ahead of its competitors thanks to the UV sterilizer.

Where to Buy the SunSun China HW-304B Canister Filter

Head to Amazon to pick up your SunSun canister filter!

sunsun china h2-304b 5-stage external canister filter

Have you tried the SunSun China 5-Stage Canister Filter yet?

SunSun Canister Filter Rated
  • Quality of Filtration
  • Build Quality
  • Accessories
  • Ease of Use
  • Value for Money

FCG Verdict

Considering its low price, the SunSun China 5-Stage Canister Filter is an incredible deal. It’s generally well made, provides excellent filtration and has a bonus UV sterilizer — almost unheard of at this price point.

It’s not perfect — the instructions leave a bit to be desired — but we certainly recommend it nonetheless.

>>> Check current price on Amazon

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