The Best 40 Gallon Fish Tanks of 2021


A fish keeping hobby is a great way to learn and nurture aquatic creatures at home. Having an aquarium entails a sense of responsibility to foster aquatic life and of maintain its natural habitat. The market of aquarium today offers a wide range of sizes for tanks as their new homes. And choosing the right size can be tedious and tricky. Fish, plants and some decorations are perfect if placed in the best 40 gallon fish tanks. This tank size is ideal for beginners who do not want to be restricted in nano aquariums. This medium sized tank can be used for breeding and is has thedimensions for keeping small and medium sized fish.

What is the Best 40 Gallon Fish Tank

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Top 5 Best 40 Gallon Fish Tanks Reviews

1. SeaClear 40 Gallon Acrylic Aquarium Combo Set


A combination set of the essentials will make you eager to keep your fish at their healthiest state with the SeaClear Aquarium. The combo of the aquarium, a light fixture and a reflector will surely get you started in building the aquarium of your dreams.

Being lightweight compared to glass aquariums, this acrylic tank is 17 stronger at 50% weight. It is also resistant to impact, is less prone to cracking, making it safe for kids and pets at home. At 40 gallons, it comes in hexagon, rectangle and other modified shapes.

This modern fish tank is safe for salt or fresh water fish keeping. The acrylic top is not removable making it a bit challenging for feeding and decorating. Past that, maintaining it is easy and easy carry around for cleaning purposes.


  • Reflector and light fixture included
  • Lightweight
  • Impact-resistant material
  • Comes in different shapes
  • Safe for fresh or salt water


  • Acrylic top cannot be removed

2. Clear-For-Life UniQuarium 40R Rect PARENT


Starters and experienced aquarists alike will surely love how this fish tank is easy to set up and install at home. With its ready-to-run mechanism, a quick set up will get you ahead in your fish keeping journey.

The built-in filtration system is reliable for maintaining the health of your fish by sieving out their waste products. This also keeps the water inside clean and suitable for growth.

The elegant design is still one of its best features with black, blue, and sapphire blue back panels to choose from. Traditional edgy aquariums may look outdated. The Clear-for-Life UniQuarium presents your fish in rounded corners for a smooth viewing experience.

Although it is not made of glass, its acrylic material is high quality and is clear enough for a seamless and glueless look on the outside. This makes it one of the best aquariums for beginners to hop on.


  • Easy to set up
  • Built-in filtration system
  • 3 back panels to choose from
  • Rounded corners
  • High quality acrylic material


  • Not made of glass

3. Vepotek 40 Gallon Acrylic Fish Tank with Black Base


Everything you need to jumpstart your aquarium dreams is in the Vepotek Acrylic Fish Tank. The inclusions in this unit are superb and are very user-friendly, perfect for starters and hobbyists alike.

The panels in this aquarium are made of high-strength acrylic, making it stronger than glass aquariums. That also makes it lighter and easier to move around the house.

Maintaining the cleanliness and health of your fish can be the most tiresome part of the journey. That may not be the case with Vepotek as it comes with a complete filtration system, making you change less frequently.

Your aquarium will stand out with its distinctive bow front design. It adds depth and heightens overall attractiveness while viewing your aquatic pets.

Durability is guaranteed with its solid base and a sleek canopy. Its only disadvantage is that it only caters to freshwater. For your growing love in fish keeping, this is surely one great purchase.


  • User-friendly set up
  • High-strength acrylic
  • Complete filtration system
  • Bow front design
  • Durable base and canopy


  • Restricted to freshwater

4. Marineland 37 Gallon Aquarium Kit with LED Light


The Marineland Biowheel does not require bothersome assembly after purchase. This aquarium kit comes with a complete guide and is easy to set up at home with no major skill required.

The fluorescent lighting that comes with this kit provides you different options to set up the mood at home. It can be switched on and off and can be turned into blue light for a midnight vibe.

Aside from the lighting, it also comes with a submersible heater to adjust the water temperatures in your region. A fishnet and a thermometer are also included with the unit.

This will worth every penny as it also provides you with food and water care samples. Aside from your basic aquarium knowledge, specific aquarium settings and mechanisms are included.

Leaving the lighting fixture too long may be damaged by corrosion. This can be prevented by taking it out occasionally and by handling it with care.


  • No assembly
  • White and blue light settings available
  • Submersible heater and thermometer included
  • Water and food care samples included
  • Easy to set up


  • Lighting fixture may corrode

5. Aqueon 40 Gallon Tank Breeder Black


The simplest aquarium is perfect for trying out if fishkeeping can fit your lifestyle. The Aqueon Breeder tank is suitable for those who are eager to try keeping aquatic pets at home.

The unit comes in a one-piece frame that is center-braced. This significantly eliminates center bowing, which can distort the view.

All panels of this standard aquarium are made of high-quality glass. This gives you a clear view of your fish as they lounge around and play throughout the day.

The top isn’t covered with canopy nor glass for easy access to your fish. The wide opening makes it easy to decorate and place plants on.

Other than fishkeeping, this tank can also be used for housing your turtles or hamster. One disadvantage of this simple tank is that other parts specific for fishkeeping like the filter, are not included.


  • Simple design
  • Center-braced frame
  • All panels are made of glass
  • Open top for easy access
  • May be used other than fish keeping


  • No filter or other fishkeeping essentials included

40 Gallon Fish Tanks Buying Guide 

Once you have set foot on starting a fish keeping hobby, it is hard to look back. Fish placed in aquariums are a feast in the eye. They come in elegant colors and are cheap therapy after work.

There are many reasons for setting your goal on 40 gallon fish tanks. Most start from scratch and consider it as a foreground on their growing passion. While some outgrow their old aquarium and decide to venture out in a bigger one.

40-gallon fish tanks are the perfect size for small and medium fish. If you have enough space in your home or office, this could be wall mounted or placed on stands.

Considering a few things before buying your tank could be helpful. This could guide you on your future purchases and if it will fit your lifestyle.

Aquarium Material

Panels of most fish tanks are made of glass. This is durable and will show a clear view of what’s going on inside your aquarium. They can be cheaper, depending on the kind but are heavier to carry and move around. They could also crack with undue stress or accidents.

Acrylic or plastic panels are gaining popularity. They are also sturdy and are sometimes stronger than glass, depending on the quality. Aside from that, they are lighter and are easier to transfer.


A vital component of your fish tank is the filter. Buying kits with filters can be advantageous. This will keep your water aerated and will keep flow inside. This also maintains the health of your fish at its best.


Natural day and night cycles are also important for the health of the fish. This will affect their own homeostatic functions and will keep them happy and healthy. Plants will love a well-lit tank for photosynthesis. But too much light can also cause algae to build up.

What is a 40 Gallon Fish Tank?


Fish tanks may be classified into their capacity in holding water. The sizes are commonly small, medium and large aquariums. A 40-gallon tank is considered a medium sized tank. It has enough room for growing plants, for keeping fish of the same or different kind, and for putting rocks and other ornaments inside.

Types of 40 Gallon Fish Tanks 

These 40-gallon water tanks come in different shapes. They may be so for decorative purposes. But aside from that, they do affect the health of your fish.

Most of your favorite aquatic pets prefer to swim through great lengths than depths. This mimic their seabed nature of swimming. There are also slow and fast swimmers that are suitable for some type of tanks. Most 40-gallon tanks come in limited shapes compared to the smaller ones.

Classic Rectangular Fish Tank

You can never go wrong with the rectangular 40-gallon fish tank. These tanks are easier to clean and maintain. They also come in various materials, with a wide variety of cover and designs to choose from.

These are perfect for most fish as the area they are in resembles much of their own home. They can swim through back and forth without much hassle. Most tanks also have rounded corners for safety and for a less edgy look.

Panoramic Hexagon Fish Tank

A hexagon fish tank gives you a wider illusion. They blend well in most homes and are a decorative fish tank that compliments the beauty inside. However, most do not recommend this kind of tank. It can be detrimental as they have less surface area. However, they are unique to be placed at home, and if you don’t have that much fish to house in.

Other notable 40-gallon fish tank shape types are:

  • Angled tank
  • Bow-front tank
  • Custom-shaped tank

Why Do You Need 40 Gallon Aquarium?

The 40-gallon fish tank is the right size for hobbyists. Most say that this is the powerhouse of tanks if you are into fishkeeping. It is not too small for a pet to be lonely, and it is not too big that requires hassle maintenance.

Having this size gives you the freedom to keep more than one kind of fish. If you are ready to venture out and be challenged by keeping another kind, smaller tanks may not permit you in doing so. This size is perfect to keep your fish company with another breed of fish.

It also gives you the liberty to have a school of fish. Your tank can be home to 20 fish of the same kind. This will keep them company and they are very fun to keep.

Some 40-gallon fish tanks are also meant for breeding. If you are into breeding your own fish, this size is right for you.

Although it takes a bigger space than smaller ones, they are surprisingly not that that hard to maintain. Once you have settled with the materials needed to get you started, disruptions are minimal. The quality of the filter matters. As well as the kind of fish and plants that are stored inside.

Consider having a bigger aquarium to expand your interest in having an aquatic pet. Plants and ornaments will not be cramped up inside. Not only you will get to enjoy having more fish, but they will also love the roomier area to live on.

Frequently Asked Questions


How many fish in 40 gallon tank?

There is a long list of species that can fit inside a 40-gallon tank. Considering its size, it gives a bigger room for the same or different kind of fish. Here are some examples of the kind of fish you can put inside a 40-gallon aquarium.

  • Guppies can be placed with 20-30 of them inside
  • Cory Catfish would love to placed inside with around 10 of them
  • Zebrafish are vivid and lively, and you can fit 20 of them in the tank
  • Mollies have a modest size and can allow you to put 15-20 of them
  • Goldfish are iconic and depending on the specific kind, you can put 2 of them inside

A community of different kinds can also be placed inside. Before buying a new one, make sure they are compatible with the ones you already have.

  • 5 Zebrafish
  • 1 Dwarf Gourami
  • 5 Guppies
  • 5 Neon Tetras

How much does a 40-gallon fish tank weigh?

The weight of this medium sized tank will depend on the material used on its panels. Glass ones are generally heavier than acrylics and plastics. On average, their empty weight is 55-58 lbs. When filled with water they could weigh at 455-458 lbs. Of course, the fish, plants and ornaments are factors for the filled weight of your tank.

What are the dimensions of a 40 gallon fish tank?

These fish tanks can come in different shapes. Most commonly, the breeder 40-gallon fish tank comes in the 36″ x 18″ x 16″ L x W x H dimensions. The long ones can come in 48″ x 12″ x 16″ L x W x H.

What is the biggest fish you can put in a 40 gallon tank?

A community-friendly fish that can fit in a 40-gallon tank is the Pearl Gourami. They love heavily-planted tanks and is peace-loving. Pearl Gourami can grow up to 4-5 inches in size. They can also have mates like Guppies and Danios inside.


The creative freedom of medium sized aquariums can be exhilarating but fulfilling at the same time. Being able to take care of your aquatic buddies in a safer and bigger environment is rewarding. Giving them the best 40 gallon fish tanks as their new haven boosts your self-esteem as a responsible fish parent. Owning an aquarium entails liabilities. Beyond this, they can bring joy to you and your family. They are easy to maintain and will keep you and your guests entertained at a low cost. The colorful and lively vibe that they exude is what every stressful and tiresome day should look forward to.

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