SunSun HW-704B Aquarium Filter – Review 2022

Sunsun have a few canister filter options and as a result, the HW-704B is the version we are reviewing here.
When looking for the best aquarium filter you want to know that the one you choose is up to the job and reliable. Let's take a look at the reasons why this Sunsun HW-704B one filter we highly recommend to keep your aquarium in tip-top condition.

sunsunHW-704B canister filter review

One of the great features of the Sunsun HW704B filter is the 5 stage filtration that it provides.  Therefore, because of this, it will do a great job of filtering your aquarium up to the highest standard that your fish will love you for.

SunSun HW-704B  filter comparison table




best fluval filter
  • Aqua stop valves.
  • 383 gph
  • Instant prime
  • Quiet operation
fluval external filter
  • Filter foam pads screen out dirt and debris.
  • Quick prime button
  • Quiet operation
  • 360 gph
fluval 406 external canister filter
  • Can handle 200 gallon tanks
  • 350 gph
  • Instant prime
  • 360 deg rotational valve attachment
  • very quiet
fluval 406 external filter

Fluval Canister Filter FX6 400 Gallon Filter

  • Can handle 400 gallon tanks
  • 563 gph
  • smart self prime system
  • Multi-directional output nozzle
  • Built with a monthly maintenance reminder
fluval 406 filter
  • Quick disconnect couplings
  • UV Sterilisation
  • Can filter up to 200 gallon aquariums
  • 525 gph
fluval external canister filter
  • Adjustable spray bar
  • UV Sterilisation
  • Can filter up to 150 gallon aquariums
  • 525 gph
fluval fish tank filter
  • Advanced Hydro-Tech LCD screen monitor
  • 265 gph
  • Can filter up to 160 gallon aquariums
  • Measures temperature and flow rate
  • On-board maintenance schedule
fluval aquarium filters
  • Adjustable telescopic spray bar
  • 345 gph
  • Easy priming system
  • 4 media basket

Features of the HW-704B Filter

The capacity of the filter is ideal for medium to larger tanks.  It can filtrate 150 gallons quite easily. This filter also has an impressive 525-gph flow. It can be used with smaller tanks with the option of an adjustable spray bar to control the output flow.  This means that if you upgrade the size of your tank, you already have the filter for the job.

The filter boasts the 5 stages of filtration.  This includes the benefit of a UV sterilizer built in by way of a UV bulb that is housed in the filter.  This ensures it will kill any unwanted bacteria and algae. This model comes with a UV safety sensor to make sure it is working correctly and not causing any harm to the filter. This is an option that not all filters have so it is worth considering when you are looking for a 5 stage filter.

How easy is the HW-704B to get up and running.

The running of the pump is up there with some of the quieter filters. The pump is designed to keep the vibration down to minimal levels. As a result, this means less output noise to spoil the aquarium ambience.

The maintenance of the filter is easily achieved with good access to all the filter.  This makes it especially relevant and can be cleaned to keep the filter in service for a long time. Spare parts are easy to acquire with good backup from Sunsun with good customer service.

The self-priming system makes getting the filter up and running a lot easier.  This avoids you having to try and get the pump started with manual siphoning.

A recap of the features of the Sunsun HW-704B

Filtration 5 stage is excellent for both freshwater and saltwater aquariums.
Furthermore, with the 4 baskets for the 4 part of the filtration, to give a mechanical biological and chemical filtration, plus the UV sterilizer it makes it one of the best all-around filters.

Another feature is the UV sterilizer takes care of any unwanted bacteria and algae that can build up in the aquarium. The 4 media trays take care of any impurities to keep your aquarium life in tip-top condition.

Capacity of the Sunsun HW-704B

With the 150 gallon capacity, therefore it is a worthy contender for someone with a medium to larger capacity tanks. With the option of the adjustable spray bar and the 525-gph, this is the reason why it one of the best performing filters available.

How noisy is the Sunsun 704B

First of all, it performs very well on the noise front. The design of the pump, which is inside the housing, keeps any unwanted noise and vibration down to a minimum which is always a big consideration when looking for a new filter.Also worth checking out the Fluval 406 and the FX6 models.

How user-friendly is the Sunsun

The easy prime button makes the filter easy to get going and the layout of the media trays, therefore, it is an easy filter to set up. As a result, it can be used by beginners and more experienced hobbyist alike.

Pros and Cons of the Sunsun HW-704B canister filter

  • The 5 stage filtration is a big plus.
  • UV sterilization is a nice added feature for taking care of that harmful bacteria and algae.
  • Nice and easy priming with the prime button makes life easier.
  • UV sterilizer safety sensor.
  • It has a good capacity of up to 150-gallon tanks with a high 523-gph
  • There is no media supplied with this model.
  • No information on the warranty length.

7 thoughts on “Sunsun HW-704B aquarium filter review”

  1. “Spare parts are easy to acquire with good backup from Sunsun with good customer service.” I haven’t been able to find parts for ANY SunSun external canister filter. Simple things like pads and impeller, but beyond that impossible. What are your resources?

      1. Could you please share that email address? I need some spare tubing for my 704b.. I’ve searched everywhere. I can’t even find their website. I bought off amazon. Love my filter, but I want to be prepared.. 🙂

        Thanks, Jenn

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