Finding the best 20 gallon aquarium is usually a great option if you are looking for a small-medium-sized tank. 20-gallon tanks are the perfect size as they are easy to use and also suitable for beginners. However, there are various options available, and choosing the wrong one can lead to a disaster for your pets.

That being said, there’s no need to worry. To help you find the best 20-gallon aquarium, we have tested multiple options on the market and curated a list so you can find the tank that suits you.

Comparison Chart

Name Material used Size (in inches)

Perfecto All Glass Aquarium

Glass 24 x 12 x 16

Tetra 20 ColorFusion Aquarium Kit

Glass 27.8 x 16.1 x 20.4

SeaClear Acrylic Aquarium

Acrylic 24 x 13 x 16

Aqueon Long Aquarium

Glass 30.25 x 12.5 x 12.75

Marina LED Aquarium Kit

Glass 30 x 18 x 22.3

Handpicked Reviews of the Best 20 Gallon Aquarium Kit

Let’s get straight into our list of the best 20 gallon fish starter kits.

1. Perfecto All Glass Aquarium


  • Resistant to scratches
  • Corrosion proof
  • It comes in great packaging
  • Long-lasting shine


  • No screen top

If you are a long-time aquarist looking to build your tank setup, the Perfecto All Glass Aquarium is an excellent tank for you. These are 20 gallon glass aquariums that don’t include any pre-built accessories such as filters or decor. So, you can have total freedom to design your tank however you want.

The tank itself is built in an industry-standard rectangular shape with 24 x 12 x 16 inches dimensions. It makes it tall enough for fish tanks and spread out enough to facilitate semi-aquatic turtle or crab habitats. Whatever setup you go for, its all-glass build is sturdy, so you won’t have to worry about any cracks or scratches ruining your pet’s home.

Along with improving strength, the glass used is fully corrosion-resistant, making it an ideal choice for both fresh and saltwater tanks. It also helps preserve the shine and transparency of the tank so it won’t turn yellow over time, unlike many other options in the market.

However, while the lack of extra items makes this tank more customizable, it is also an added effort. That is because looking for everything needed for a tank, such as a filter, plants, etc., can be time-taking and cost a decent amount of money.


The Perfecto All Glass Aquarium is a sturdy tank that doesn’t come pre-built or with extra parts. It makes it a great option if you are planning on using your decor and accessories. It is made out of glass, which helps improve durability and makes it corrosion and scratch-resistant. That being said, as it doesn’t come with any parts, you will have to spend some time looking for things like a top cover, filter, etc.

2. Tetra 20 ColorFusion Aquarium Kit


  • Customizable LED lighting system
  • Includes decor
  • It comes with various accessories
  • Easy installation


  • Slightly expensive

The Tetra 20 ColorFusion Aquarium Kit is a comprehensive package that makes setting up a new aquarium easy. It comes with various accessories, so even if it’s your first time, you’ll have everything needed to get your tank ready for plants and fish.

Along with an aquarium hood, plant packs, and more, this kit comes with a Tetra Whisper 20 Filter. This filter is perfect for this tank and has a powerful filtration system that can keep your aquarium water crystal clear. Also, the whisper filter functions very silently, making it great for use in bedroom or office environments.

One thing that sets this kit apart from many other aquariums is the included Color Fusion Universal LED lights. These lights looked visually stunning during our testing process, and they were able to completely change the ambiance of the tank according to the color we set it on. The lights are also well integrated into the tank for an even spread, so you can always have your aquarium looking fresh and new.

Along with this, the filter also comes with anemones right out of the box. Anemones are great for decor, and they also sway with filter currents and are great for fish to hide and relax. It makes the tank much more suitable for smaller fish who may want to hide from the flowing water at times.

That being said, with all these accessories and parts, a common concern is that the aquarium will be challenging to set up. That is not the case with the Tetra 20 ColorFusion Aquarium, as it comes with a TetreCare experts guide that makes installation easy. So, you won’t have any trouble even if you are a beginner.


If you are a beginner looking to build your first fish tank, the Tetra 20 ColorFusion Aquarium Kit is a comprehensive package perfect for you. It comes with all the accessories and parts you will need to set this tank up for your pet fish to enjoy. Also, installation is simple as this tank comes with a helpful installation guide.

3. SeaClear Acrylic Aquarium


  • Multiple shape options
  • Lightweight
  • Impact & crack resistant
  • Includes light fixture


  • Slightly Expensive

If you are looking for impact-resistant and sturdy 20 gallon acrylic aquariums, the SeaClear Aquarium is a suitable option for you. This tank is made out of acrylic, which is 17 times stronger than glass while still weighing only half. It comes especially handy if you move a lot or plan to shift the aquarium often.

A common concern with acrylic tanks is that the seams and edges tend to fog up and ruin the look. It is not the case with this tank, as SeaClear has designed it to have nearly invisible seams that impressed us a lot. Thanks to this feature, you can look at this tank from any angle and get a clear, unobstructed view of your flora and fauna.

This tank also comes with a great setup and starting combo with a reflector and electrical light fixture. The light is excellent for aquariums in darker indoor areas as it can simulate daytime which is excellent for amphibians and fish. Also, the reflector improves light yield, so you can simulate a bright daytime environment if needed.

Unlike most other tanks on this list, SeaClear offers this tank in a hexagonal shape option. It is great if you are looking for a decoration tank useful for certain types of aquariums, such as seahorse habitats.


The SeaClear Aquarium is a heavy-duty tank that is built with a robust and impact-resistant acrylic design. Along with this, the tank comes in a kit with many useful parts, such as an LED light and reflector to help you set it up. Also, it is available in a rectangular as well as hexagonal shape that is great for decorative aquariums.

4. Aqueon Long Aquarium


  • High-quality construction
  • Clean silicon edges
  • Multiple trim styles
  • One-piece center-braced frame


  • No accessories included

The Aqueon Long Aquarium is a reliable 20 gallon fish tank starter kit that is built to last. It is made entirely from high-quality glass and has slightly larger dimensions than most 20 gallon tanks, making it great for decoration aquariums.

The glass used in this tank is also great at avoiding scratches, corrosion, and even natural coloring a few years down the line. It makes it a great and safe option for all kinds of freshwater and saltwater tanks, even for amphibians.

Many people have a common worry with glass tanks because they are heavy, and the sharp edges can hurt people or even crack upon dropping. Thankfully, Aqueon has fixed this by adding a layer of clean silicon throughout the boundaries of this tank. These silicon edges make it a lot easier to place, carry and even help in softening edge impacts. Also, they won’t ruin the look of your tank, as you can choose between clear or black edges to suit your surroundings.

That being said, as the tank is made out of glass, it is pretty heavy and due to this, make sure you have a sturdy stand that can safely bear the weight of this aquarium.


If you are looking for a reliable and high-quality tank, the Aqueon Long Aquarium is an excellent choice for you. It is built out of scratch and corrosion-resistant glass, making it safe for use with all kinds of fish. Also, it comes with silicone edges to keep you and the tank safe from any impacts or injuries.

5. Marina LED Aquarium Kit


  • Sturdy build quality
  • Energy-efficient LED lighting system
  • It comes with a filter
  • Set up instructions are included


  • Not crack resistant

If you are looking for a tank that leaves nothing to be desired, the Marina LED Aquarium Kit is an excellent 20-gallon tank for you. It has a sturdy build quality and is perfect for both aquatic and semi-aquatic habitats.

This aquarium is very easy to maintain with its glass body as glass is corrosion resistant and doesn’t change color over time. Along with this, glass tanks tend to look more transparent as they aren’t prone to any sorts of scratches.

Marina has made great use of the glass by incorporating a beautiful natural daylight LED lighting module into this tank. This lighting module connects to the aquarium canopy, which is also included in the package. So, if you plan on keeping this tank in a darker area, lighting is something you won’t have to worry about, and your fish can enjoy a subtle yellow light whenever needed.

This 20 gallon fish tank setup also comes with various accessories that make it user-friendly. One accessory that we liked the most was the Marina Slim S series clip-on filter. This filter easily clips onto the side of this tank and offers powerful filtration. Moreover, it is easy to maintain thanks to a unique quick-change cartridge design.


The Marina LED Aquarium Kit is a great all-rounder 20-gallon tank set up. The tank itself is high-quality and built with a corrosion-resistant glass body. Apart from this, it also comes with a canopy-fitting LED light that can mimic natural daylight, making it great for amphibian tanks.

Things To Consider While Choosing a 20 Gallon Fish Tank

Here’s a list of some things you should consider when looking for a 20-gallon tank.

– Tank Material

Most aquariums available in the market are either made of glass or acrylic. These are very different in various aspects ranging from the look, strength, corrosion resistance, etc.

When it comes to tanks made of glass, they tend to be much more long-lasting and also resistant to corrosion. Moreover, these tanks don’t stain over time and are highly resistant to scratches and scuffs. However, glass tanks tend to be heavier than their acrylic counterparts and are prone to chipping and cracking.

On the other hand, acrylic tanks benefit from being very lightweight and, in most cases, cheaper than glass tanks. They are also better at dealing with falls and rarely crack or chip. That being said, they do scratch quite quickly and are also known to stain over years of usage.

So, looking at this, if you are looking for a sturdy and permanent aquarium setup, glass is probably better for you. They will be easier to maintain, and the heavyweight won’t be a problem as long as you have a sturdy stand. Although, if you purchase a tank for temporary purposes or plan to move often, acrylic may be a better option because of its lightweight and crack resistance.

– Included Accessories

Finding the parts needed to set up an aquarium can be pretty tricky if you are a beginner. That is because you need various products and accessories like a filter, canopy, thermometer, and much more. To solve this problem, many companies have started offering tank kits that come with various included accessories to make setting up your fish tank a lot easier.

Along with primary devices and parts like the canopy and filter, some kits also come with additional items such as LEDs to improve your tank lighting conditions and aesthetic or anemones that provide a suitable resting place for fish. That being said, for more expert aquarists who want to customize their tanks fully, it may be best to avoid these kits and look for single tanks.

– Aesthetic Features

One of the most essential parts of a tank is decorations and aesthetics. Tank owners use different styles and items to create stunning aquariums that look excellent and ideal habitats. To help with this, many aquariums and tank kits are coming out with aesthetic features such as transparent edges and LED lighting systems.

So, before buying a tank, decide how you want the layout to look. After doing this, you can look for a tank with features and parts to match that vision. For example, if you want a tank in an orange-colored room, looking for one with a multicolor LED might suit the surroundings.

Equipment You’ll Need for a 20-Gallon Tank

Let’s go over some of the equipment you will require to set up your 20-gallon tank.

– Filter

Almost every fish tank, especially one as large as the 20-gallon ones, will require a proper filter. This filter is responsible for removing various unwanted elements such as waste, debris, bacteria, etc., from your tank’s water. Also, filters aid in the aeration of your tank, increasing oxygen levels and promoting plant and animal health.

Filters also require regular maintenance in the form of cleaning and replacement of media and cartridges. It should be done as soon as bi-weekly or as late as every few months, depending on the instructions for your filter.

– Substrate

The material utilized to fill up the base of your tank is its substrate. The substrate is very important and impacts the aquarium’s water chemistry, filtration, and the well-being of your fish. Different types of substrate will offer various benefits; for example, peat is soft and great for burrowing animals, and gravel provides sites of bacterial colonization. Along with this, the substrate is also a large part of your tank’s aesthetic appeal.

– Lighting

Lighting in aquariums is primarily used for two purposes. One is to simulate a natural habitat, and the other is for decoration.

Warm lights are often used to replicate the natural environment and mimic sunlight. These lights are usually kept on during the day and off at night to simulate the sun’s cycle. They are also required by some species of plants and animals to stay healthy and also for photosynthesis.

On the other hand, decoration lighting tends to be more colorful and is installed to make your aquarium look pretty. For example, many filter kits come with color-changing LED systems that you can set to almost any color you want.

– Hood or Cover

The hood is the covering that goes on top of your aquarium. While it is a pretty fundamental part, the hood is very important for various reasons. Firstly, having a hood helps keep any dirt or debris from falling into your tank. Also, if you have energetic fish, having a hood will stop them from jumping out of your tank. And last but not least, a cover will reduce the rate of water evaporation.

– Heater

Many species of fish and marine animals, especially tropical ones, will require a hotter environment. To make your tank habitat warm enough for them, buying a good aquarium heater is essential.

That being said, if you are planning to house water snakes or other reptilian species in your tank, you will need a different kind of heater. These animals require more direct heating, and for them, heating coils tend to work the best.

Frequently Asked Questions

Let’s discuss a few frequently asked questions related to 20 gallon reef tanks and aquarium kits:

1. How Many Fish Can Go in a 20-Gallon Aquarium?

While there is no cemented rule as to how many fish you can keep, make sure that you don’t overfill your tank as it can lead to a build-up in toxicity and harm your fish. As a general guideline, you can keep twenty 1-inch fish, or ten 2-inch fish, in a tank that is 20 gallons in capacity.

2. Is a 20-Gallon Tank a Good Size?

Yes, 20-gallon tanks are a great medium-sized option and are suitable for beginners venturing into aquatic pets. That is because 20-gallon tanks are easy to manage while still being large enough to safely dissipate harmful waste and toxins that build up in aquariums.

3. What Animals Can Live in a 20-Gallon Tank?

Depending on how you set up your aquarium, a variety of animals such as frogs, fish, crabs, starfish, etc., can live in a 20-gallon tank. That being said, it is hard to mix various animals as if you build a 20 gallon reef tank, it would be challenging to keep multiple fish due to the semi-aquatic landscape.

4. Can Betta Fish Be in a 20-Gallon Tank?

Yes, tanks that are 20 gallons in size or larger have enough space for multiple male bettas to live together. However, that does depend on the specific situation, and it would be best to place them in one at a time to avoid any sudden stress or conflict.


We hope you found a suitable fish tank that matches your preferences and fits your budget. However, if you are still confused and want our final recommendations, we are here to help. Even though all the options on our list are top-tier fish tanks, there is one that stands out. After thoroughly testing the devices, our top pick for the best 20-gallon tank is the Perfecto All Glass Aquarium.

It is a sturdy glass tank that doesn’t come with any pre-made parts allowing you complete customizability and freedom to design your own tank. It is also well built and uses strong corrosion and scratch-resistant glass, making it a great product to last you for years. That being said, the lack of accessories might not be suitable if you are looking for a quick and easy tank setup.

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