55 vs 75 Gallon Aquarium, Which Should You Choose?

Last Updated on July 16, 2022 by cmoarz

Choosing the right aquarium for your home or office is a big decision. There are many factors to consider, such as cost, size, and type of fish you want to keep. Two of the most popular sizes are 55 gallon and 75 gallon tanks. So, which one should you choose? We say 75, but…

Here are some things to consider when making your decision on whether to buy a 55 gallon vs 75 gallon.

Direct comparisons to a 75 gallon aquarium and a 55 gallon aquarium

55-gallon aquarium

Size Dimension: 48″ x 13″ x 21″

Empty Weight: 107lbs

Filled Weight (Water): 641 lbs

Surface Area: 576 sq inches

75-gallon aquarium

Size Dimension: 48″ x 18″ x 21″

Empty Weight: 140lbs

Filled Weight (water): 875 lbs

Surface Area: 864 sq inches

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What these differences mean realistically

The differences, while seeming somewhat small on paper, are actually pretty significant. The 75-gallon aquarium is actually 36% larger than the 55-gallon aquarium. This means that you have nearly 40% more space to work with when stocking and decorating your tank.

The increased size also provides some key benefits for the fish. A larger tank will have more stable water conditions, which is better for the fish.

You will be able to choose larger species, or many smaller species of fish with a 75-gallon aquarium.

Of course, with a 36% larger tank comes with 36% more weight. Weighing in at 875lbs full, the 75-gallon aquarium is much heavier than the 55-gallon aquarium.

While the physical footprint isn’t much larger, the weight footprint is, and you will need a stand that can accommodate the increase. Stands of this nature can become more expensive than the aquarium itself so be sure to factor that in when making your decision.

The extra weight also makes moving the tank more difficult. It’s not impossible, but something to consider if you think you may need to move the tank in the future.

Cost comparison – Which is more expensive

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This is why you should choose a 75 gallon over a 55 gallon

When it comes to creating the best aquarium/aquascape possible, the surface area is king. The more surface area you have, the easier it is to keep nitrates and other pollutants in check. This is due to the increased water-to-air ratio. A 75 gallon aquarium has nearly 50% more surface area than a 55 gallon aquarium.

The extra size and weight of a 75 gallon aquarium give you more options for substrate depth, rockwork, and planting.

A 75-gallon aquarium also provides a better environment for fish. The increased size and stability is better for their health and happiness.

In general, a larger tank is easier to maintain than a smaller one. This is because there are more gallons of water to dilute pollutants, and a larger water volume is more stable than a smaller one.

The increased surface area of a 75 gallon aquarium also means more oxygen exchange. This is important because it helps to keep your fish healthy and prevents them from getting sick.

In our own personal experience, Everyone we know who started off with a 55 gallon tank eventually upgraded to a 75+ gallon tank.

We aren’t saying a 55 gallon isn’t a good tank, It is, and compared to a 10 or 20 gallon, it’s far more stable and easier to maintain. But, when given the choice, we would always choose a 75 gallon aquarium over a 55 gallon.

Especially when you consider the price point, where a 75 gallon isn’t much more expensive than a 55 gallon.

If you are looking to create the best possible aquarium, whether it be for a freshwater aquarium or a saltwater aquarium, choose a 75-gallon tank over a 55-gallon, at least, In our experience.


Owner of AquariumGravel.com and also owner of actual Aquarium Gravel believe it or not! ;). Setting up beautiful aquarium sceneries and habitats since I was very young. Enjoy!