55 Gallon Tank Dimensions – Types, Problems and How to Select

When setting up your first 55 gallon fish tank, it’s important to consider factors like tank size and space. Because, ultimately, focusing on ideal 55 gallon fish tank dimensions creates a healthier and more comfortable habitat for your aquatic pets.

This “55 Gallon Fish Tank Dimensions” guide is here to help you figure out if the tank fits in your room and how to choose the right 55 gallon fish tank.

Moreover, if you want to learn what problems could arise with keeping large tanks such as a 55 gallon, do stick to the end for all the details.

Disclosure: This article contains affiliate links. When you follow a link to purchase the products, I sometime earn a commission, at no additional cost to you. Read my full disclosure here

Why Do You Need to Know 55 Gallon Fish Tank Dimensions?


Determining where to place a tank in your home requires knowing the 55 gallon fish tank dimensions, which are 48 inches long, 13 inches wide, and 20 inches tall (121.92cm L x 33.02cm W x 50.8cm H). This measurement basically tells you how much room your tank needs.

Customizing Area for Different Species

Knowing how big your tank is essential if you want to add different kinds of fish. Because different fish require different amounts of space, it’s helpful to know how big your tank is so you can choose fish that will fit in well.

Maintaining Water Quality

Water quality is directly impacted by tank size. It establishes how often and how much treatment your tank’s water needs to be given to keep your aquatic friends in the best possible health.

Avoiding Overcrowding

Fish that are overcrowded may be stressed and more prone to illness. Sufficient dimensions help you choose the ideal number of fish to keep your aquatic community healthy by preventing overcrowding.

The 55 Gallon Fish Tank Dimensions

55 Gallon Tank Weight

Regarding 55 gallon tank weight, the 55 gallon fish tank dimensions are considered a medium-sized tank that presents both advantages and disadvantages. Understanding the dynamics of weight, which are impacted by material selection, is essential.

Material Difference

There is a weight contrast introduced by the choice between acrylic and glass. Glass is the traditional choice and has a heavy appearance. Acrylic is a lighter substitute and weighs about 20–30% less than glass aquariums.

Filled vs. Empty Aquarium

The 55 gallon tank weight which is made of glass weighed around 80 pounds. However, the story takes a serious turn when water appears. The filled glass tank weighs nearly 456 pounds, with each liter adding 8.34 pounds. Even though acrylic is lighter, when filled, it still belongs in the heavyweight category.

The Dimension of Saltwater Aquarium

About saltwater aquariums, the 55 gallon tank weight increases to approximately 465 pounds when submerged in water. The scene is set for a more significant presence when you add the extras like gravel, decor, and equipment.

It’s not just common knowledge to know how full or empty your tank is; it’s a safety measure against possible disasters. The site selection must support the 55 gallon tank weight to guarantee peaceful coexistence free from structural problems.

55 Gallon Tank Length

Contrary to popular belief, a 55 gallon tank length has a significant impact. The water’s surface area is directly impacted by its length and width, which in turn affects your fish wellbeing. Imagine the surface area as the underwater equivalent of the stage for an important performance.

A 55 gallon fish tank length is almost 44 inches. Making a comfortable home is more important than aesthetics when it comes to 55 gallon tank length. More oxygen can mix with the water in a longer tank, which is essential for fish breathing. It also gives natural swimming patterns plenty of room. In essence, keeping a healthy and balanced underwater environment depends greatly on the length of your tank.

55 Gallon Tank Width

A basic guideline to keep in mind when setting up a tank is that the 55 gallon tank width should be at least half the length, if not slightly more. To simplify, consider this: if the front length of your tank is 60 cm, try to make it at least 30 cm wide. Why is this relevant? It’s similar to giving your fish enough leeway to swim and investigate.

Therefore, a 55 gallon tank width measures around 13 inches almost. Consider giving them a large house instead of a small flat.

55 Gallon Tank Height

It is advised to set your 55 gallon tank height at roughly half of the edge length, which is the ideal height for fish to feel comfortable. Consider this: a height of about 15 cm would be appropriate if the edge length of your tank is, let’s say, 30 cm.

Here, the 55 gallon tank height is estimated to be 20 inches almost. Moreover, the professionals recommend adding a few extra centimeters to allow for the substrate layer and water level, which are typically located slightly below the edge.

Types of 55 Gallon Fish Tank

Standard 55-Gallon Tank

This rectangular tank, which is 48 inches long, 13 inches wide, and 20 inches high, is a popular choice. It is the standard model. Made of glass, it offers pristine clarity for observing your aquatic friends.

Standard 55 Gallon Tank

55-Gallon Corner-Friendly Tank

These tanks have a unique pentagon shape and are made to nestle comfortably into corners. Their 38-inch length, 27-inch width, and 22-inch height allow you to maximize the square footage of your room while incorporating a distinctive element.

55 Gallon Corner Friendly Tank

Large 55-Gallon Breeder Tank

The breeder tank is the solution if you want to give your fish more space to move around horizontally. Its dimensions are 36 inches long, 18 inches wide, and 21 inches high, making it wider than a typical tank and perfect for spawning and nest-building activities.

Large 55 Gallon Breeder Tank

55-Gallon Hexagon Tank

With six sides and dimensions of 24 inches in length, 24 inches in width, and 24 inches in height, this hexagon tank adds visual flair to any space. This unusual shape gives your aquatic display a fascinating touch.

55 Gallon Hexagon Tank

How to Choose the Right 55 Gallon Fish Tank?

  1. Assess the Space in Your Room: Begin by examining the area where you intend to position the tank. 48 inches long, 13 inches wide, and 20 inches high (122 cm x 33 cm x 51 cm) are the typical dimensions of a 55-gallon tank. Verify that there is adequate space.
  2. Know the Weight: Eighty pounds, or thirty-six kg, make up an empty 55-gallon tank. It rises to about 456 pounds (207 kg) when filled. Make sure the surface or stand can support this weight.
  3. Select Your Tank Material: For your 55-gallon tank, choose between acrylic and glass. Although glass is heavier, it scratches less easily. Acrylic can scratch more readily but is lighter and more impact-resistant.
  4. Examine the Lid: A sturdy lid is essential to keeping curious pets at bay and preventing fish from leaping out. Moreover, it lessens the evaporation of water.
  5. Examine the Lighting: In addition to improving the tank’s aesthetics, built-in lighting promotes plant life and inhibits the growth of algae. When assessing the lighting arrangement for your tank, take these things into account.

Common Problems with a 55 Gallon Fish Tank

Fish Size Mismatch: One common problem is underestimating the amount of space needed for a particular species of fish. Certain species, like Red Tail Sharks and Dojo Loaches, might not be able to survive in a 55-gallon tank unless they are housed alone or with extremely small tank mates.

Problems in Fish Community Planning: It can be difficult to gauge the right tank size for a variety of fish in a communal setting. Think about Comet Goldfish, which require at least 75 gallons to live happily in groups. Furthermore, be careful not to pack too many plants or decorations in, leaving plenty of open swimming room for your aquatic friends.

Compatibility Issues: Community fish compatibility can be problematic, even in a 55-gallon tank that is fairly large. Certain fish that are normally peaceful, like dwarf angelfish, can become aggressive when they are in small areas.

Waste Accumulation: In a 55-gallon community tank, effective waste management is essential. The fish’s health may suffer from the buildup of ammonia and other waste leftovers. Although they are important, filters need to be the right size for the tank. Filters alone are insufficient to maintain water quality; frequent manual water changes (about 25–50% every two to four weeks) are necessary.


To sum it up, choosing a longer and wider aquarium over a taller and narrower one is crucial for the well-being of your fish. The 55 gallon fish tank dimensions significantly impact fish behavior, giving them enough space to move around, rest, and establish territories.

Moreover, the surface area of the water is important for gas exchange, allowing toxic gases to escape and oxygen to be absorbed – essential for the respiratory health of fish. While a tall narrow tank may work, it provides minimal benefits for the fish.

Scott Evans

View all posts