55 Vs. 75 Gallon Fish Tank Showdown (Size, Weight & Cost)

55 gallon vs 75 gallon

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If you want a large-sized aquarium for your home, you’re probably wondering whether to get a 55-gallon fish tank or go even bigger with a 75-gallon option since they have the same length of 4 feet.

That’s true, the length makes them look substantially larger than the mid-sized aquariums like a 20-gallon or even a 40-gallon (breeder), but there are some important differences to consider before making your final decision.

And that’s why I put together this guide for you. Below, I’ll cover the 55 gallon vs. 75 gallon aquarium debate in detail and help you decide which is right for your situation.

Aquarium Size

The chart below detail the size specifications for 55 and 75-gallon fish tanks. As you can see, the only difference is in width; 75-gallon tanks are 18 inches wide front to back, while 55 gallons aquariums are only 13 inches wide.

Tank SizeDimensions (L x W x H)
55-gallon48″ x 13″ x 21″ (122 cm x 33 cm x 53 cm) 
75 gallon48″ x 18″ x 21″ (122 cm x 46 cm x 53 cm) 

The Benefits

The extra width of the 75-gallon aquarium isn’t just for show; it actually provides some important benefits that a 55-gallon tank doesn’t have.

More Stocking Ideas

55 Vs. 75 gallon: extra width

Simply put, the larger the fish tank, the more fish you can have. It’s a decided advantage because the large footprint gives you much more flexibility with your stocking options. 

As I mentioned before in the post about the disadvantages of 55-gallon aquariums, the limited depth makes it difficult to keep certain large centerpiece fish that need ample space to swim side to side and turn around, from the well-known favorites like Oscar(Astronotus ocellatus) cichlids all the way to exotic flowerhorn cichlids.

From my years of experience, I’ve come to the conclusion that 55-gallon aquariums are the bare minimum size to decently house a good number of medium to small active fish. If you want to add any larger centerpiece species, I recommend going with the 75 gallon aquarium.

Looking for more ideas on stocking your 55-gallon aquarium? Check out this HUGE list.

Surface Area

Perhaps the second important consideration associated with the extra width of the 75-gallon aquarium is the increased surface area.

Why does this matter? Because a larger surface area means more oxygen exchange at the water’s surface. It’s an important factor when you decide to keep an overcrowded Lake Malawi aquarium or fish that require high levels of dissolved oxygen like Oscar.

Hiding Places

Broader tanks also allow you to create more shelters and hiding places for your fish by using driftwood, live plants, and rocks. 

This is especially necessary for cichlid fish tanks, as it gives them more places to claim as their own without worrying about their aggression and territorial behaviors in the aquarium.


75 gallon vs 55 gallon fish tank: easy to decor

In addition to all of the functional advantages due to the extra width, 75-gallon tanks also look a lot nicer and more “finished” since they provide a larger canvas to really get creative with your aquascaping, and let’s face it… a wider tank is just easier to decorate.

The Disadvantages

There are, of course, a few disadvantages to going with the larger 75-gallon aquarium over the 55-gallon because of the extra width. These include:

More Maintenance Work

A wider fish tank generally holds more water and can take longer to clean, especially when trying to remove algae growth.

It’s not a huge difference, but it’s something to consider if you’re short on time.

Limited Access Locations

Where to place an aquarium will play a significant role in which one you should get. A wider 75 gallon fish tank will have a harder time fitting through narrow doorways and hallways than the 55 gallon aquarium, let alone its hoses and accessories that come with it. 

You need to ensure that you have enough space in your room to accommodate the additional width, both when moving it into your house and having ample room surrounding it so you can enjoy and properly maintain it.


Weight is also an issue when selecting an aquarium, especially if you consider getting a larger tank. This means taking into account the tank’s empty and filled weight.

Here are the estimated weights of standard 55 and 75-gallon glass aquariums. Acrylic aquariums will weigh half that.

Tank SizeEmpty WeightFilled Weight
55-gallon78 lbs.850 lbs.
75 gallon140 lbs.1050 lbs.

Absolutely, the winner is the 55 gallons aquarium.

If you plan on buying a 75-gallon aquarium, ensure that your flooring can handle such a heavy load when filled with water, substrate, decor, and fish. Needless to say, you will need a specialized aquarium stand that can support the weight of a 75-gallon aquarium, which is surprisingly heavy. 

Therefore, a 55-gallon aquarium is the better choice for those looking for a balance between size and weight, while the 75-gallon aquarium is better for those who have the space and can accommodate the extra width and weight.


The last factor to consider is cost—both in terms of the upfront purchase price as well as the long-term costs associated with running a larger aquarium.

Regardless of the initial purchase price or ongoing costs, as you might expect, the 75-gallon aquarium will cost more than the 55-gallon—sometimes significantly more. 

Initial Purchase Cost

A 55-gallon aquarium kit is going to be the more affordable option when you’re making your initial purchase. The kit includes everything you need to get started, like the tank, filter, heater, lid, and often even gravel and decor.

On the other hand, you will need to buy each of these items separately for a 75-gallon aquarium, which will cost more.

Additionally, it will take a little more money on filter media, gravel, plants, and decor to fill a 75-gallon aquarium since there’s simply more bottom area and water volume.

Long-Term Costs

It’s not just the initial purchase that costs more with a 75-gallon aquarium—the ongoing costs are also higher. This includes the cost of water, electricity, fish food, and any medications or other supplies you might need.

Closing Thoughts

Some say that the 55-gallon aquariums are best, while others say 75-gallon tanks are the better option. It comes down to a matter of personal preference and your budget and living situation. 

I know personal preference certainly is important, but consider all of the factors we’ve discussed— size, weight, and cost —before making your final decision.

What’s your stocking plan? Do you have the space for a 75 gallon aquarium? Do you mind doing a little extra work to maintain it? Are you willing and able to spend more money upfront and on an ongoing basis?

Answer these questions honestly and you’ll be well on your way to choosing the right aquarium.

If I miss anything about the fish tank showdown between 55 gallon vs 75 gallon, don’t hesitate to reach out. I’m happy to help!

Article Sources:

  1. Does Aquarium Tank Width Matter? [TheSprucePets]
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Ivan Yeoh
Ivan Yeoh

I’ve been working with fish for the past 12 years, and I can honestly say that it has never been a dull day. In my time, I’ve worked at the largest fish farm in Singapore – so you could say I know a thing or two about keeping things running smoothly in watery environments.

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