Best 100-Gallon Aquarium 2024 & Buyers Guide

Keeping fishes as pets is fun. They do not just give life to your room, but also having fish as a pet has its benefits to the owner. Having a fish as a pet can help you reduce stress, blood pressure, and heart rate and improve the behavior of those who suffer from Alzheimer’s. Fishes are also quiet, and they do not take much space in your home. Once you buy your first fish, you can surely never stop buying again, resulting in needing to buy a bigger aquarium.

People usually buy small tanks, around 10 to 20 gallons. Then they will continue to upgrade to a bigger, more advanced one, like a 50-gallon tank. Buying a bigger aquarium may seem a bit intimidating, but it is better than buying a fishbowl, especially for your first purchase of fish. However, if you think you are ready to have another upgrade, a 100-gallon aquarium might be for you.

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CADE REEF 900 S2 Aquarium

Elos Diamond Series 120 Aquarium 90 Gallons

Waterbox Aquariums Reef 100.3 +Plus HD Edition


35.4 x 27.6 x 23.6 inches

47.24 x 22.44 x 34.25 inches

36 x 24 x 22 inches


105 gallons

90 gallons

100 gallons


not stated

not stated

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White or Black

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The best 100-Gallon Fish Tanks in 2024

Since your fish doesn’t take up much space to begin with, you should invest in a high-quality habitat suited for them. Here are the best 100-gallon aquariums you can buy today:

1st Elos Diamond Series 120 Aquarium 90 Gallons



  • Dimensions: 47.24 x 22.44 x 34.25 inches
  • Weight: N/A
  • Capacity: 90 gallons
  • Material: Glass
  • Color: Black
  • Shape: Rectangular

Aquarium Elos Diamond Series 200 offers a very good option for people who want to build their own underwater landscaping. There is a possibility to purchase a cabinet, a pump, and an overflow directly with it. This offers the advantage that all equipment is perfectly coordinated. Who needs only one part, however, can also purchase only this.


  • Diamond Glass with 60cm tall with polished edges
  • ELOS QuietDrain overflow and protection against snails
  • Metal Frame and Magnetic PVC panel
  • Provides an unusual vision because of the hight
  • After gluing the aquarium is “seasoned” for at least 25 days before being moved to ensure quality of incomparable bonding.
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2nd CADE REEF 900 S2 Aquarium



  • Dimensions (L x W x H): 35.4 x 27.6 x 23.6 inches
  • Weight: not stated
  • Size: 105 Gallons
  • Color: Black
  • Inclusions: Aquarium

The 900 S2 aquarium from Cade Reef has a volume of over 100 gallons. It provides a solid foundation to create a saltwater aquarium or a reef aquarium. It is a combination of aquarium and cabinet, which provides optimal preparation for pump and other equipment.


  • Top-notch quality
  • Diamond edge flat polished
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3rd Waterbox Aquariums Reef 100.3 +Plus HD Edition



  • Dimensions (L x W x H): 36 x 24 x 22 inches
  • Weight: N/A
  • Size: 100 Gallons
  • Color: White or Black
  • Inclusions: Removable Filter Socks, Gate Valve Overflow Adjustment, Water etched glass overflow, Cabinet, Prefabricated Plumbing Kit

Waterbox Aquariums provides hobbyists with a customizable foundation to design their dream aquarium. With every purchase of the Waterbox Aquariums Reef 100.3 +Plus or anything from the Reef +Plus series, there will be a Stand, Sump, Plumbing Kit, and Filter Socks included. There will also be two Aqua Illumination Hydra 32 HD LED Light Fixtures and two AI HMS Hydrea Tank Mounts.

The Waterbox Aquariums Reef 100.3 +Plus features a 10 to 19 mm Starphire Ultra-clear Beveled Glass (rimless) Water etched glass overflow box, Rubber Mat Under Tank, Dual adjustable overflow returns, and Prefabricated proprietary plumbing kit. It also offers a safety drain, whisper-quiet overflow style, flexible return pipe, and quick disconnect unions.


  • Comes with a Cabinet
  • Comes with an LED Light Fixture
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4th Waterbox Aquariums Reef 100.3



  • Dimensions (L x W x H): 36 x 24 x 22 inches
  • Weight: N/A
  • Size: 100 Gallons
  • Color: White or Black
  • Inclusions: Removable Filter Socks, Gate Valve Overflow Adjustment, Water etched glass overflow, Cabinet, Prefabricated Plumbing Kit

Another awesome aquarium from the Waterbox Reef Aquariums, the Waterbox Aquariums Reef 100.3. Waterbox Aquariums provides hobbyists a customizable foundation to design their dream aquarium. The Waterbox Aquariums Reef 100.3 features a rimless 10-19 Starphire Ultra Clear Beveled Glass and water etched glass overflow box. It also has a Prefabricated proprietary plumbing kit, precision gate valve, safety drain, whisper-quiet overflow design, and flexible return pipe.

The Waterbox Aquariums Reef 100.3 also has some special features. Some of these are the cabinets, which have leveling hardware, included upon purchase made by a world-renowned cabinet maker. A cabinet also comes with a removable filter sock.


  • Comes with a Cabinet
  • Comes with an LED Light Fixture
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5th Waterbox Aquariums Peninsula 4820


  • Specifications
  • Dimensions (L x W x H): 47.2 x 19.7 x 21.7 inches
  • Weight: N/A
  • Size: 100 Gallons
  • Color: White or Black
  • Inclusions: Full Glass Overflow, Dual Adjustable Return Nozzles, Glass Overflow Cover, Removable Weir Teeth

Waterbox Aquariums make sure that they give their customers a quality product and a lot of customizable aquariums. That is why Waterbox Aquariums Peninsula 4820 is another awesome aquarium from them. The Waterbox Peninsula series is designed for those who want their aquarium to have a more decorative approach. The Peninsula or “Room Divider” offers an elegant solution to break up a room and is viewable from 3 sides.

The Water Aquariums Peninsula 4820 features a full glass overflow made entirely of glass, dual adjustable return nozzles for precise water agitation, and a newly designed removable weir teeth system that allows the uses for easy maintenance and cleaning. The Peninsula 4820, like the other aquariums in the peninsula series, are designed for easy assembling without gluing required.


  • Comes with a Cabinet
  • Easy Assembling
  • Safety Drain
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6th Red Sea Reefer Deluxe XL 525 System



  • Dimensions (L x W x H): 125 x 60 x 60 inches
  • Weight: N/A
  • Size: 138 Gallons
  • Color: White or Black
  • Inclusions: Adjustable height Skimmer Chamber, Heavy Duty Levelable Plywood Cabinet, ReefLED

Red Sea’s REEFER series provides advanced hobbyists with a solid foundation for building a fully featured reef or marine aquarium. REEFER series is designed for easy operation while still giving advanced hobbyists the freedom to install an unlimited choice of lighting, circulation, controllers, and filtration, making it great for people who like to customize their tanks.

The Red Sea REEFER Deluxe XL 525 also incorporates the all-new ReefLED RL90 lighting units. Moreover, it has a dedicated 3W Moonlight channel that can give off low light levels for a reef-safe nighttime viewing. To ensure the pump compartment’s constant water level, all REEFER includes an integrated automatic freshwater top-up unit.


  • Comes with a Cabinet
  • Customizable
  • Comes with the all-new ReefLED
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Why should I buy a 100-Gallon Aquarium?

Buying bigger aquariums can be a bit intimidating and more expensive than smaller tanks; however, acquiring a big aquarium, even for first-time buyers, does have a lot of benefits. The most obvious reason why buying a bigger tank is beneficial is that the fish will have a bigger area to swim in; they will not get stressed, compared to swimming in a compact space, and they also get to socialize with other fishes once you decide to get more fish to accompany the lone one. There will be a big space for the fishes to play, jump, swim, and swirl freely. In contrast, if you start with a small aquarium, you might realize that there will not be enough space for all your fishes.

Large tanks will also give you the chance to explore more on aquascaping. Aquascaping is the art of arranging aquatic plants, rocks, sands, stones, cavework, and driftwood into an eye-pleasing landscape, kind of like underwater gardening. By getting a bigger tank, you can have a large space to practice your aquascaping. Decorate the aquarium in any way you please without affecting the swimming space for the fish.

Getting a bigger tank may be expensive, but it can also help you save money over time. If you want more fish, you can put them in the same tank as your fish before because there will still be a lot of space left for them. With a bigger aquarium, you can also promote a better chemical dilution because the chances of overstocking a large fish tank are less. This will also result in a pollution-free ecosystem for a long time.

If you still decide not to get a 100-gallon aquarium and just settle for a smaller tank, that is also fine since you still need to learn first to have a great experience with a bigger tank. Learning how to manage a smaller tank first before getting a bigger one is a great move too. Getting an aquarium does have its benefits, after all, regardless of its size. Fish tanks in your home can help you in reducing your stress. Looking at the fishes, swimming around can be peaceful. Not only spending time around your fishes and the fish tank is helpful to your well-being, but taking care of them can also be beneficial.

Keeping fishes as pets can also help you to have a better sleep quality. Going to sleep is not that easy for many people, so watching their pet fish playing and jumping around the aquarium also helps them sleep.

Taking care of tanks, big or small, takes a lot of effort and time. However, all of these will be worth it once you see your fishes playing around the aquarium. Be sure to research well first before choosing the right aquarium for you. An aquarium will suit your needs. Especially there are a lot of kinds of tanks available, so choose your aquarium wisely.

How do I choose the best 100-Gallon Aquarium?

Choosing the best aquarium for you can be a difficult task. You have to choose the best aquarium that will fit not just your habitat but also match the type and size of your fish. If an aquarium does not fit well in its surroundings, it is hard to appreciate its beauty. Here are some of the factors to consider before buying an aquarium that will be best for your needs:


When choosing an aquarium, budget usually comes first, and it is not wrong. Keep a list of the aquariums you would like to purchase and narrow them down by comparing the price that will work well with your budget. Of course, there will be pros and cons to it, and the aquariums will not look and function as the other aquarium. There are downsides when buying an aquarium with a cheaper aquarium, but you have to work with what you have and learn to compromise.


It is best to choose a product with the highest quality. Always check the specifications of the aquarium before buying it. You want to look for an aquarium that will last for almost a lifetime. Do not forget to also check for the manufacturer if they are well known about the aquariums they make. Put the type of tank you want to have in consideration too. Do you want it to be glass or acrylic? There are many varieties of acrylic tanks, and they are clearer and heat-resistant. Glass tanks, on the other hand, are much cheaper and are more resistant to scratches and damage.


One of the things that a person usually thinks of before choosing an aquarium is the size. If this is the first time you will buy an aquarium, you might be considering buying a smaller tank, but as said earlier, it is still better to buy a bigger tank rather than investing in a cute one. While buying a smaller one is logical, it is not advisable. Given that a bigger tank costs more, but in the long run, it will help you in saving money in terms of water, fish food, and you might not need to upgrade to a bigger tank.

You might also want to consider where in your house you want to put your aquarium. You do not want to get a large tank when you are going to place it in a small room, or maybe, you want to buy a large tank and put it in a room, and buy more large aquariums so that you can have a mini ocean park in your home.


Another factor that can affect the decision to choose the best aquarium is the shape. Different fishes prefer different aquarium shapes and swimming spaces. Get to know your fish and research first about their behavior and preferred tanks before buying one. Territorial fish, like cichlids, prefers lots of bottom space, so be sure not to get a narrow or tall tank for them; Active fish like barbs and danios swims a lot, so they need a bigger space to swim to, which means a rectangular, longer aquarium will suit them well.

Also, keep in mind where you are planning to place your aquarium in your house because it can also affect the shape of your tank. You do not want your tank to look out of place once it is sitting in your house. Do you want it in the corner of your house, or maybe at the center of it and use it as a divider of the rooms in your home. You may also want to place it on the counter between your kitchen and the living room.


Aquariums require a stand to keep it off the floor and raise it at an appropriate height. Some tanks are heavy, depending on their size, so using furniture like tables is not recommended. When choosing a stand, check for its weight capacity to avoid future potential disasters. You can also choose a stand that is specifically designed to carry the aquarium you want to purchase.

Aquarium stands can be wood or metal. They also come in various styles and qualities, some are very simple, and some are very stylish, so also keep that in mind when purchasing a stand. Choose a stand that will look like it really belongs in your home. Choose a style that will fit your room’s location and ambiance, and make sure that it is sturdy.


When purchasing an aquarium, you can be a little excited and imagine what it would look like when it is already installed in your home. Do you want it to have a lot of accessories and decors? You may want to plan the accessories and decorations you want to have in your aquarium first before purchasing them because you might not need them.

Practice your aquascaping first by making a sketch. Do you need gravel and substrate? How many aquarium plants do you want in your aquarium, and what are they? Maybe you also want to have ornaments and make a cave for your fish. After you finish your planning, you can now purchase the materials you need and make the most beautiful aquarium there is.


A tank cover serves many purposes, but most importantly, it keeps your fish inside the aquarium. Some fish like to jump out of the water, but any fish has the ability to get out of a tank that does not have a lid. So be sure also to purchase a quality lid that also suits your style.

Some tank lids are made of plastic. Some are glass. Most of them have access doors, but only a few have a glass strip where you can attach your light on. Do you want to have easy access in terms of giving food to your pet fish? Do you want it to be well lit?

Do I need a Heater for a 100-Gallon Aquarium?

Though some fish species do not require a heater since they can survive a wide range of water temperature, some fish still require tank heaters, especially tropical fish, so that the temperature stays steady even during colder seasons.

Fish are cold-blooded animals which means that they rely on the water temperature to support their body temperature, which means that you must provide heat for your fish to help them survive and maintain the right temperature for them. There are a lot of kinds and types of heaters available that affect differently in every fish.

Read more about it here: Best Aquarium Heater.

Types of Aquarium Heaters


Hanging Heater

Hang on tank or immersible tank heater mounts typically on the rear of the aquarium with a suction cup, hook, or another fastening device at the tank’s edge and sits in the water to heat the tank. They are only partially submerged, which makes them less efficient, but still providing basic heating. Hang-on tank heaters are usually used in smaller tanks. When used in bigger tanks, it is advisable to use two or more hanging heaters. Immersible heaters are not recommended for brackish and saltwater setups.


Submersible Heater

This heater is completely submerged in the tank water and mounts at the back of the tank, horizontally or vertically, usually placed near the substrates. A submersible heater should be placed next to the filter’s inlet to heat the water as it goes to the tank. This heater also provides more accurate and efficient heating than hanging heaters, especially with larger tanks. A submersible tank heater is encased in a toughened plastic tube or a glass prone to cracking if the unit overheats.


Substrate Heater

The Substrate heater is commonly used as an addition to other heaters. They usually come in the form of wires and are fixed at the base of the tank. This is most popular in the 90s, especially in tanks with plants, because it provides a gentler water movement compared to other tanks that stimulate the growth of roots. Substrate heaters are less common now and are quite expensive.

There are other types of tank heaters. You may also want to check them out. Now that you have an idea of some of the heaters and already have an idea which heater should you use, how can you choose the right size of a heater to use for your aquarium?

The perfect Size for an Aquarium Heater

The size of the water heater you are going to purchase depends on the tank’s size. Your equipment’s quality and efficiency will be the determiner in finding the right size of a heater to purchase, along with other minor factors. Looking for the perfect size of a tank heater should also be based on the tank’s water volume, the average temperature in the room where it is located, and the target water temperature for the tank.

More wattage is required when the tank has a larger water volume. The basic rule is to use between 2.5 and 5 watts per gallon of water volume in the aquarium. If you use more than one heater, all units’ overall heating capacity should result in the required heater wattage. 300 watts output in a heater should be used for tanks above 100 gallons. Any aquarium above 125 gallons would require a heart with more than 300 watts of output.

Read more about it here: Aquarium Heater Size Guide.

Conclusion – Best 100-Gallon Aquarium

Choosing and buying aquariums that suits your need can be a hard time, but all the time and effort in finding the best aquarium for you will pay off once you get to see the fishes in your 100-gallon tank, swimming happily. Before purchasing a new aquarium, just be sure that you checked all the factors that might affect your experience with the tank, and make sure that you will buy what is best for you. Different aquariums suit different personalities and styles and the type of fish you are going to buy or that you already have. Put into consideration the place where you are going to put the aquarium and the fish you are going to put in it.

Buying a new and larger aquarium requires research and knowledge to know if you are ready to have one, so before rushing to the store, and buying a new tank, ask yourself if you are truly ready, and go purchase yourself a new aquarium.


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