Best 20 Gallon Fish Tank Kit of 2021 – The Top 8

best 20 gallon fish tank

If you are considering buying fish for an aquarium, you’ll want to take a look at this review of the best 20-gallon fish tank kits of 2021. This guide could help you in making the right decision on your purchase.

When getting started with a fish tank, you want to make sure that you select the tank that is right for your needs. In other words, you want to pick an aquarium that will be ideal or the type of aquatic life you plan on keeping.

So, What is the Best 20-Gallon Fish Tank Kit of 2021?

Here’s what you will learn in this blog:

Why You Should Buy a 20-gallon Fish Tank

If you are looking to get started with an aquarium and freshwater fish, you’ll want the right tank. You’ll want the best 20-gallon fish tank for your needs.

Because I’ll tell you based on my experience, setting up the wrong tank can be a major friggin’ headache. Not only because you put the time and money into the tank, but when all is said and done, your tank is not a match for your needs.

This blog is to help you avoid that situation. The goal of this article is to review the top 20-gallon aquariums and give you some good info and advice for your tank.

The “best” fish tank for your needs, though, might not always be the perfect tank for someone else’s fish keeping hobby.

And there are many reasons why.

freshwater fish in tank
The type of fish you are going to keep as pets in your aquarium can impact the size of the tank you will need.

For example, if you plan on having sizeable aggressive fish like Arowana, then obviously you will need a decent size tank. I mean, a 10-gallon tank is not going to work for an Arowana.

Also, if you decide on keeping a pet crayfish, which are known to be aggressive, you’ll want a tank big enough for them and other fish.

Personally, I always recommend 20-gallon fish tanks to anyone looking to keep fish, especially beginners. Overall, I think they are a better choice.

Why 20-gallon Fish Tank Kits are Perfect for Getting Started

20-gallon fish aquariums are great for many reasons. They allow you to grow your hobby in terms of the number of fish you are going to keep, but also, they are easy to maintain.

And with fish tank kits, an aquarium hobbyist can get started almost immediately. Meaning, a kit comes with everything they need to get their tank up and running.

20 gallon fish tank

The best 20-gallon fish tank kit will usually include a water pump, water filter, water conditioner, heater, fish food, skimmer net, and sometimes even more.

Currently, in my 20-gallon tank, I have a pet blue crayfish and a neon tetra.

The tank is still plenty big enough for me to add even more fish, though.

In a nutshell, these tanks are just big enough, efficient, give you some flexibility, and are still very easy to work with.

A Review of the Best 20-Gallon Fish Tanks of 2021


aqueon 20 gallon fish tank

1. Aqueon LED Aquarium Kit 20H Black

If you look, the Aqueon LED Aquarium Kit 20H Black is a kit that comes with everything you need to get started, minus the water of course. Oh, and the fish, don’t forget about them. I guess those are just the things you will have to take care of yourself.

The Aqueon is a solid starter kit or upgrade for a hobbyist looking to move up from a 10-gallon fish tank or an even smaller aquarium.

Like many of the newer tanks, this Aqueon includes a bright LED light that is not only efficient but will last a good while. This, of course, will save you money on having to purchase new lighting.

You will love this tank because not only does it come all the parts you need to get going, but it is so easy to set up.

Just as a note, always remember to cycle the water in your tank before adding any fish. This is a crucial step, as I’m sure many of you already know. Don’t worry. I’ll remind you about cycling again later on.

This fish tank kit comes with the following:

  • A bright LED light that fully illuminates the tank
  • QuietFlow 10 LED PRO power filter (Basically, when the red light flashes, you need a new filter.)
  • A preset heater that will automatically keep the water in your fish tank at 78 degrees
  • A guide that shows you all you need to know to set up the tank
  • Fish food
  • Water conditioner
  • A fishnet
  • A thermometer that sticks on your tank

The Aqueon was the very first fish tank that I owned.

When I moved, I got rid of it, but I sure do miss it. It worked like a champ, was easy to set up, and easy to maintain.

learn more 20-gallon fish tank

2. Tetra 20 Gallon Complete Aquarium Kit

tetra fish tank
Usually, when you are getting started setting up your fish tank, you have to think about what decor and ornaments that you will put in it.

Will you have an Easter Island head placed in the center of your tank? Will you add a Sphinx or a pyramid? Or will you simply put in some PVC pipes and rocks?

There are just so many options.

These are all of the things you have to consider when it comes to the look and feel of your fish tank.

But with the Tetra 20 Gallon Complete Aquarium Kit, you literally have that work done for you. At least part of it anyway.

That’s because the tank comes with all of the major components to run your tank (as listed below).

However, the kit also includes Wonderland Plant Multipacks and a blooming white anemone. The anemone is a pretty cool feature, actually.

These additions to the kit will help give your tank personality. Not to mention, you can add any other ornaments you would like.

Another cool thing about this tank is the Color Fusion (color-changing) LED. It will really make your tank pop.

This is an LED light that rotates between different colors. However, it will allow you to choose just one color.

This LED lighting feature is just one more reason why this aquarium made the list of the best 20-gallon fish tank kits.

Remember, you will, of course, still need to choose the color of gravel. I’d suggest black gravel, personally. It really helps set off the colors in your tank. And between the lighting options, gravel choices, and the fish you select, you can really make this into a unique looking aquarium.

*Note, this is very similar to the Tetra listed above. Although, the ornaments, plants, etc. in this tank vary a bit. Also, the LED color changing light is a main feature of this tank.

This fish tank kit comes with the following:

  • LED light with multiple color settings. (You can keep the color one setting.) 
  • Wonderland Plant Multipacks
  • Blooming White Anemone
  • A UL Heater
  • Tetra Whisper Water Filter
  • Water conditioner

learn more 20-gallon fish tank

3. Marina LED Aquarium Kit


The Marina LED Aquarium is on our list as one of the best 20-gallon fish aquarium kits because it is rated four out of five stars on Amazon.

Also, besides a great rating, this tank is also very affordable. And affordability is always nice when buying anything, especially aquariums. That’s because as you probably know by now, they can get pricey.

Again, this tank also includes everything you need to get up and running. It’s an excellent buy for a beginner or someone upgrading from a smaller tank.

It is also a tank that offers a little bit of growing room.

This fish tank kit comes with the following:

  • LED light
  • Water filters
  • Water pump
  • Water cycling supplement to help cycle your fish tank
  • Water conditioner
  • Fishnet

learn more 20-gallon fish tank

4. Marineland (Aquaria) AMLPFK20B Aquarium Kit

marineland 20 gallon
I’ve always been a fan of Marineland fish tanks. And in my opinion, they make some of the best 20-gallon fish tank kits around. Heck, I’ve owned a couple of these tanks. They are very high-quality, and mine was a great tank.

This aquarium has a couple of things I really like.

One is the Biowheel filtration system. This isn’t anything that you will see in the other tanks mentioned in this blog.

This wheel works perfectly with your tank to help filter out toxins that are harmful to your fish and other life in your fish tank. It helps create an optimal biological filtration system in your aquarium.

If you are looking to keep the water clean and stable with little effort, this is a great option.

Also, this tank comes with an LED light that mimics daylight. But, the light also has three settings.

It has a regular LED setting, a low-energy setting, and a blue light setting.

Obviously, the low-energy setting is a great way to save on power usage and costs.

This fish tank kit comes with the following:

  • An LED light with three settings
  • Water filters
  • A Biowheel for the ultimate biological filtration system
  • A water cycling supplement
  • Water conditioner
  • Fish food samples
  • Fishnet

learn more 20-gallon fish tank

5. SeaClear Acrylic Aquarium Combo Set

seaclear aquarium 20
This is probably one of my favorite 20-gallon fish tanks on the list. Even though I’ve never owned one personally.

One reason why this tank is such a standout, and so awesome, is because it’s acrylic. And being acrylic, plants, fish, and anything else in your tank become incredibly more vivid in color.

This tank is a great piece to feature in an area of your house that gets a lot of traffic. It can improve the look of your aquarium life by quite a few notches.

Also, acrylic is much stronger than glass while at the same time being lighter than glass. So this will make for a much more durable and sturdier tank, one that is more resistant to chips and damage.

But yes, if you are keeping colorful fish or blue crayfish, this tank would make those colors intensify simply because of how the tank is made.

Note: This tank is not a kit that includes everything you need to get started. You would need to buy a water pump and other accessories on your own.

This fish tank kit comes with the following:

  • 4″ light
  • An acrylic tank that is stronger than glass but weighs less

learn more 20-gallon fish tank

6. GloFish Aquarium Kit Fish Tank with LED Lighting and Filtration

This is a great aquarium kit for a neon set up. It comes with literally everything you need to get up and running.

It has an LED hood, heater, Whisper 20 water filter, and GloFish 13” LED light stick.

To me, one of the coolest things is that this tank comes with a yellow anemone, plant multipacks, water conditioner, and fish food.

And trust me, the blue LED lighting can really set off an aquarium.

The tank includes:

  • LED hood
  • Heater
  • Whisper 20 water filter
  • Glofish 13″ light stick

learn more 20-gallon fish tank

7. Tetra ColorFusion 20-Gallon Fish Tank

tetra 20 gallon tank

This is another great fish aquarium. It’s a tank from Tetra. I’ve owned a couple of their tanks over the years.

It comes with everything a beginner needs to get started in the aquarium hobby—with a little room to grow. Now, it does come with fake plants, which many people are not a fan of. However, it depends on what you are keeping in your tank. If you are like me and keeping a blue crayfish (not shrimp), they are great at destroying and eating your real plants.

The bottom line, this tank is easy to set up. It’s not so big you can’t find a place to put it, and it comes with all that you need.

This tank includes:

  • Multi-color LED lights
  • Plants that glow under the LED light
  • A tank filter
  • A tank heater
  • A hood

learn more 20-gallon fish tank

8. Buying a Used 20-Gallon Tank

cleaning a fish tank
This option isn’t always one that people will go with unless they’ve kept fish for a while. This option probably seems like a lot of work to those new to the fish keeping hobby.

Because if you simply buy a used fish tank and nothing else, you’ll still need to buy all of the other parts to make the tank functional.

Yes, it is true, you can’t just put your fish into a fish tank of water without a pump, cycled water, etc. But, by starting with only a fish tank, you get to decide on which accessories you want to add.

This means you can make choices on a wide selection of water pumps, heaters, ornaments, and anything else.

And to find used fish tanks can be easy. Simply check out thrift stores, eBay, of course, Craigslist and yard sales.

Once you have your tank, the design is all up to you.

20-Gallon Fish Tank Set-Up

I’ve written pretty extensively about how to set up a 20-gallon fish tank.

In short, you’ll want to put your tank together using the step-by-step guide. This is usually pretty easy. It doesn’t include a lot of work or time. You, of course, just want to make sure you do it right.

After you have your tank set up, though, is when the important stuff takes place.

This is when you will need to condition the water and cycle the water in your tank.

In short, conditioning water simply makes tap water safe for any fish that you will add to your fish tank.

However, cycling your tank can be frustrating for some, but not if you do it the right way.

Cycling a tank is the process of setting a biofilter. Basically, a process that neutralizes and removes toxins created by fish who pee and poop in the tank.

Can you imagine swimming in your pee and poop? Wait, stop, don’t imagine that. That’s just gross.

At any rate, this water cycling step in setting up your aquarium is vital to the survival of any fish that you put in the tank. So make sure you do it right.

Recap

Just to recap on what was discussed in this blog.

We discussed how buying an aquarium should be targeted towards what your needs will be. In other words, buy a tank that is ideal for the types of fish you will keep. And with buying a 20-gallon tank, you have room to add several different types of fish.

Also, we discussed why 20-gallon tanks are great tanks all around and especially for those starting out with fish keeping. A tank that is as big as 20 gallons will be big enough to enjoy and easy enough to maintain.

This article also reviewed several affordable fish tank kits. Ones that we consider to be the best on the market.

Most of the fish tanks reviewed come with everything needed to get up and running.

These tank kits include not only an aquarium but in many cases a water pump, filtration system, thermometer, LED light, fish food, water conditioner, and set up guides.

Outside of buying a new tank, there is always the option to buy an old tank. The downside of this, though, is that even though you may find a quality tank online or at a yard sale, you’ll still often need to purchase other accessories to make the tank functional.

Finally, we talked about the importance of conditioning your tank’s water and cycling the tank before adding any fish.

Without cycling the tank properly, many of your new fish will quickly die. This, of course, wouldn’t be a good thing.