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Marineland Penguin 350 Review 2023 – Pros, Cons and Verdict

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By Lindsey Stanton

Although there are A LOT of aquarium filters out there to choose from, finding the right one can be difficult. There are in some ways too many options to chose from but the key is finding one that best serves the size and purpose of your tank

Today we are doing a detailed Marineland Penguin 350 review, looking at the features that this particular filter offers and how good it actually is compared to other filter options available.

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Our Marineland Penguin 350 Review

arineland Penguin 350

The Marineland 350 is a fairly good filtration unit. While it is not the biggest, most powerful, or most efficient unit, it does the job and it does the job quite well at that. Let’s take a closer look at the features of this particular filter right now to give you a better idea of what it is all about.

Filtration Capacity

The first feature or aspect of the Marineland Penguin Filter that needs to be mentioned is that this thing is rated for aquariums between 50 and 70 gallons. Now, it is not exactly the most efficient filter on the market, so if you have a very heavily stocked tank, we would not recommend using it for anything over 60 gallons.

However, if you have a lightly stocked tank, it should do just fine for a 70-gallon aquarium. In terms of processing power, this particular filter can process around 350 gallons of water per hour, which is not bad at all.

If you are using it with a 50-gallon tank, this means that the Marineland Filter can process the total water capacity of the tank 7 times per hour. We do have to say that this is very impressive. It is not something that you see too often with any kind of aquarium filtration unit.

Hang On Back

To be clear, the Marineland 350 is a hang-on back filtration system. For one, this helps make it quite easy to install. All you really need to do is place it on the rear of your aquarium, secure it down with the clips, and you are more or less ready to go. Now, we do like hang on back filters quite a bit.

The reason for this is because they do not take up any space inside of the fish tank itself. Filters that are inside of tanks tend to take away way too much space that could otherwise be used by the fish, or for plants. This is not a problem with this particular filter.

With that being said, it does stick out from the back of the aquarium quite a lot. In other words, you will need a good 5 or 6 inches of clearance behind your aquarium if you want to fit this thing on your fish tank. Simply put, this filtration unit is quite easy to use, which is quite a bonus.

Now, on a side note, you will need to prime this thing manually. It’s not a huge deal or a big pain in the butt, yet it is worth noting nonetheless.

goldfish in planted tank with rocks, wood, and decorations
Image: S-F, Shutterstock

Filtration Types

One feature that we personally like about the Marineland 350 filtration unit is the fact that it engages in all 3 major types of filtration. This is quite important when it comes to keeping any fish tank clean and clear, especially if you have a heavily stocked tank with lots of fish and plants.

This thing comes with simple-to-use filtration cartridges. They are all in one filtration cartridges that can simply be replaced in one go when they are dirty. The downside here is that there is no indicator which tells you when they need to be replaced. You just kind of need to know by the look of it.

However, the fact that these cartridges perform chemical and mechanical filtration at once is pretty neat. This helps to remove all kinds of solid debris, as well as toxins, chemicals, and other odors from the water. In terms of biological filtration, the Penguin Filter comes with a patented bio-wheel.

The bio-wheel builds up with beneficial bacteria which helps to eliminate ammonia, nitrates, and nitrites from the water. One thing that needs to be said here, although this filtration system works well, it is kind of loud as it turns, especially the impeller and the bio-wheel.

Finally, this thing also comes with a mid-level adjustable intake strainer. This strainer helps to remove all kinds of solid debris from the aquarium. This is quite useful because it means that your actual filter media won’t get dirty and used up quite as fast as it otherwise would.


This particular filter does have small waterfalls on each side which return the filtered water into the tank. This can be quite beneficial as it helps to bring oxygen into the depths of the aquarium water.

Fish need oxygen to breathe, and the more fish you have in a tank, the more dissolved oxygen needs to be present in the water. Yet, the waterfalls do make a fair amount of noise. Now, some people actually find this gurgling noise to be quite relaxing, while it drives other people right up the walls.

  • Fairly durable outer shell.
  • Very good processing power.
  • Ideal for fairly heavily stocked tanks.
  • Does not take up room inside of the tank.
  • Simple to hang on the back.
  • Great 3 stage filtration.
  • Easy to remove and replace filtration cartridges.
  • Makes a fair bit of noise.
  • Intake strainer needs to be cleaned often.
  • Needs a fair bit of clearance behind the tank.
  • Does not look all that attractive.

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In case you do not like or feel the Marineland Penguin 350 is the right option, the Marineland Magniflow Canister Filter is a possible alternative to consider. Now, it is not rated to be used for aquariums quite as large as the Marineland Penguin is, but it does have some key differences which may attract you.

Marineland Magniflow canister filter

While the Magniflow is rated for smaller aquariums, it has somewhat better filtration power. What we mean by this is that it comes with more media and has more room for media, not to mention that you can be much more selective with media with the Magniflow than with the Penguin.

At the same time, whereas the Penguin is a hang on back filter, the Magniflow is a canister filter, so it does not take up room inside of the tank and it does not require clearance in the rear. Ease of placement is a pretty big deal here.

With that being said, while it does not have waterfalls to aerate the tank, it also doesn’t make noise due to there not being any waterfalls. On a side note, the Magniflow appears to be a little more rugged and durable than the penguin.

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When it comes to the Marineland Penguin 350, our final verdict is that it is indeed a pretty darn good filter to use. It might need a lot of clearance and it might be a little too loud for some, but it does have great processing power that you just won’t find with most other hang on back filters.

You Might Also Be Interested In: Marineland Magniflow c360 Canister Filter Review

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