Best 20 Gallon Fish Tanks for Your Fish’s Perfect Environment

The 20 gallon tank has been called many names, but one that truly stands out is “The best beginner tankâ€, as some would call it. In many ways, that statement is true. As an entry-level tank, it is quite affordable, and it is easier to set up. The main reason for this is that most 20 gallon tanks are sold as a set, meaning that the package includes other items needed for the aquarium as well, like the lighting, the heater, the filter, etc.

Selecting the best 20-gallon will require identifying several key buying factors. Should you not know where to start, you'll find the following aspects make the process much more manageable. So before we look at the reviews, let’s discuss a few:

  • Placement: Buyers must select a place to put their tank before buying it. Otherwise, they might purchase a 15 to 20-gallon fish tank without anywhere to accommodate it. It’s surprising how many people end up finding themselves in this position.
  • Construction Materials: Don’t purchase a tank without researching the materials used in building it. In other words, buyers must ensure their tanks have high-quality, durable constructions. Most 20-gallon fish tanks will fall into two types, acrylic or glass. Acrylic tanks often favor someone looking for a top option for the cheapest bargain. Meanwhile, glass tanks are more durable but come at a higher price.
  • Setup: Some fish tanks already have everything set up, from LED lighting to filter, whereas others are completely blank. Products with accessories will be more expensive, but they'll save the time and effort to find suitable decorations and/or filters.

If you'd like to try it out, here's a list of the best 20 gallon fish tank that I have tried.

Best Overall


Tetra Complete Aquarium Kit

✔ Excellent filter
✔ Scratch-resistant
✔ Includes artificial plants


Premium Choice


Marina LED Aquarium Kit

✔ Has an LED hood
✔ Has a water conditioner
✔ Free fish food


Editor’s Choice

GloFish NV33823

✔ Easy to clean
✔ Lightweight design
✔ Durable construction


Top 20 Gallon Fish Tank Reviews 2023

1. Tetra Complete Aquarium Kit


If you are searching for a reliable and durable aquarium kit that offers all the convenience that you need as a fishkeeper, the ideal product that you should try is the Tetra 20 Gallon Complete Aquarium Kit w/Filter Heater LED & Plants.

There are so many things to like about this particular 20 gallon aquarium kit. First is the LED lighting. It has a natural light condition that illuminates the inside of the tank. The effect is truly mesmerizing because it is as if I am looking at the tank during the daytime. The LED hood does a magnificent job of keeping the light inside.

I have observed that the tank is scratch-proof. This is a good feature because it protects the glass from scratches due to accidental contact with pointy objects. This also prevents the tank from breaking. This is a very important feature to me because my children have a pet cat. Its claw can really scratch the surface of the glass tank.

Meanwhile, the filter performs admirably. It has a three-stage filtration system that keeps the water clean and clear at all times. Because of this, my aquarium doesn't have floating particles, harsh chemicals that could stain the water and cause a bad smell, and harmful organisms which could affect the health of the fish inside.

The heater is another feature that I consider absolutely beneficial. It saves the fish from freezing during harsh winter temperatures. Without this added bonus on the aquarium kit, I wouldn't have to keep replacing my precious pets again and again.

What I consider this product's shortcoming is that the filter seems a little small for the aquarium.

  • The tank is scratch-resistant
  • Has an LED lighting
  • Has an LED hood
  • Has a preset heater
  • Has an excellent filter
  • Includes artificial plants
  • The filter seems a bit small for the tank
Considering all of the important information discussed above, I can safely say that the Tetra 20 Gallon Complete Aquarium Kit w/Filter Heater LED & Plants is a terrific product. It has every feature a hobbyist need: a sturdy 20 gallon tank, an excellent filter, luminous LED lighting with a hood. The heater is also a marvelous addition to the package. Finally, it has artificial plants that could help you decorate the inside of the tank.

2. Marina LED Aquarium Kit


When it comes to a 20 gal fish tank kit, nothing beats the features offered by Marina LED Aquarium Kit. If you are searching for a top-tier tank kit, it is a wise decision to include this product in your shopping list.

What I really appreciate about this 20 gallon tank kit is the presence of an amazing filter. I can always count on this little aquatic machine to remove any standing particles, harsh chemicals, and harmful organisms through its three-stage filtration system.

The heater is another reliable tool included in the package. I can rely on this tiny contraption to prevent the fish from freezing during critical moments of the winter season. Other aquariums don't have a heater included in the kit; that's why I had trouble finding the perfect one that would complement the design of the tank.

Another exciting feature of this tank kit is the LED lighting. The light is very cool in the eyes; it is neither glaring nor dim. It's just very perfect for the size of the tank. The lights are very inviting, warm, and pleasing. Once the LED is turned on, it becomes a very magnificent decorative piece that can bring beauty to any living space in the home.

What I don't like about this aquarium kit is how the fish food floats on the surface of the water. The remaining fish food just clutters the water as it waits to be filtered. Inasmuch as I want to give my fish a little amount of food to prevent it from clouding the surface of the water, they would easily get hungry. Then, I would have to dedicate another part of my time just to see that the fish are well-fed.

  • Has an excellent filter
  • Has a preset heater
  • Has an LED lighting
  • Has an LED hood
  • Has a water conditioner
  • Has a free fishnet
  • Comes with free fish food
  • The fish food floats and clouds the surface of the water
After taking all of the important information into account, I can say that the Marina LED Aquarium Kit is a terrific product. It has every item that both beginner and seasoned hobbyists are looking for: a reliable 20 gallon tank, a good filter, a heater, and LED lighting with a hood. The package also comes with a water conditioner so that tap water can accommodate the fish. If you need to have a 20 gallon aquarium kit immediately, then this product will provide you a smooth fishkeeping experience.

3. GloFish NV33823 Aquarium Kit

GloFish’s NV33823 20-Gallon Aquarium Kit earns a place on this list with its endless number of impressive features. I’d have to start by expressing praise for its durable construction made from scratch-resistant glass. It shouldn’t have any trouble staying in excellent condition for several years.

The product’s appearance is also improved with an included blue LED light. It offers this fish tank a more modern aesthetic, which is perfect for my setup. As a result, I don’t have to worry about the tank ever being an eyesore like my previous 10-gallon fish bowl.

Buyers won’t have to worry too much about setting it up. GloFish did everyone a solid by including all the necessary equipment for an effortless setup. Therefore, I wouldn’t hesitate to recommend this all-in-one model with lid to newbies or other inexperienced aquarium lovers.

In the same vein, this tank is even easier to maintain with its user-friendly cleaning process. I only have to replace the filter cartridge monthly and change 25% of the tank water. Suffice it to say, it’s a perfect setup for me, considering my forgetful nature.

Another aspect worth mentioning is its lightweight design. It tips the scale at only 34 pounds, so most people can carry it without needing help.

But this twenty-gallon tank does come with a flawed filter. It was noisier than expected, which could be an issue for sensitive ears.

  • Durable construction made from scratch-resistant glass
  • Stylish appearance with blue LED light
  • All necessary equipment provided for effortless setup
  • Easy to clean and only require monthly maintenance
  • Lightweight design weighing only 34 pounds
  • The included filter is noisier than expected.

Thankfully, I had a usable filter from my previous round fish bowl to replace it. This defect became a non-issue quickly once I set up my old filter. Therefore, I appreciated it as one of the top-quality GloFish tank ideas available to aquarium hobbyists.

4. Aqueon LED Aquarium Kit

Aqueon LED Aquarium Kit 20H Black

20 gallon tanks with complete setup are perhaps one of the top-rated things that a fishkeeper considers a “good find.†If you are looking for a 20 gallon aquarium kit that you can use in your own place, the best 20 gallon fish tank that you can purchase is the Aqueon LED Aquarium Kit 20H Black.

One of the features that I appreciate about this aquarium kit is the filter. It has an excellent three-stage filtration system. It effectively keeps harsh chemicals that could stain the water or poison my fish and plants, filter out undesirable particles such as small pebbles and fish food, and harmful organisms such as bad bacteria and fungi which could compromise the health of my aquatic pets. Furthermore, it operates very quietly. The filter's sound doesn't disturb the peace and quiet inside my home office.

Another admirable feature of this aqueon 20 gallon kit is the LED lighting. The white glow not only illuminates the contents of the tank but also bring out otherworldly beauty. In addition, the LED hood equally distributes the light inside the tank and prevents it from spilling outside.

What I find disappointing about this tank kit is the absence of a hinge on the LED hood. Every time I feed the fish, I always have to lift the whole hood just to have complete access to the tank. I wish there were a way to just simply lift one side of the hood the other remains on the other side without having to exert tremendous effort. I believe that a hinge will rectify this issue.

  • The filter works quietly
  • The filter has an excellent three-stage filtration system
  • Has an awesome white LED light
  • Has a reliable and low-profile LED hood
  • The filter has an LED indicator that informs when to change cartridges
  • Has a preset heater
  • With free fish net, water conditioner, stick-on thermometer, and fish food
  • The LED hood has to be taken off completely
All in all, I can honestly say that the Aqueon LED Aquarium Kit 20H Black is an excellent product. It has everything that a hobbyist needs: a sturdy 20 gallon glass tank, filter, LED light, a preset heater, and an LED hood. The package comes with free fish food, a water conditioner, a stick-on thermometer, and a fishnet. These freebies will definitely save any fishkeeper a great deal of money in the long run.

5. All Glass Aquarium AAG10021 Tank


For those who are looking for a sturdy and reliable blank tank only, the most trusted one in the market is definitely the All Glass Aquarium AAG10021 Tank.

I admit that this is a little different from the other brands that come with complete 20 gallon fish tank accessories. This gives me an opportunity to experiment and expand my decorative horizons. While I couldn't put different species of fish together, I was able to try different gravel and corals as part of aquarium decoration.

Another benefit that I get from purchasing just a blank tank is the chance to breed some of my fish. Because of an empty 20 gallon tank, I was able to breed my guppies successfully. Now, I can give two to three guppies to my friends, relatives, and neighbors who are also into fish-keeping.

What I don't like about this open 20 gallon tank is how it easily gets dirty. Since the tank has no canopy or hood, dirt and other free-falling particles can get into the water easily. Also, fish and snails can easily escape through the opening. One time, a lizard pooped and it went straight into the open aquarium. The little guppies thought it was fish food and they munched it straight away. So right now, I'm using an improvised cover made from discarded plywood just to keep the tank covered all the time.

  • Comes with black and oak styles
  • The glass is durable
  • Lightweight
  • Lets natural light in to help plants thrive
  • It gets dirty easily because it has no cover
  • Fish and snails can easily jump out
After listing all of the advantages and disadvantages, I conclude that the All Glass Aquarium AAG10021 Tank is a great tank kit. Despite being only a tank, it is a perfect space for breeding fish, for experimental decoration, among others. The tank is made from durable glass so you don't have to worry about replacing it very soon.

6. SeaClear Acrylic Aquarium Set


If you are tired of using glass tanks as aquariums, there is one great alternative that you will really enjoy using—presenting the SeaClear Acrylic Aquarium Combo Set: the perfect tank to replace your traditional aquariums.

There are many things that I really like about this product. First is the material. Honestly, it's nice to see a little break from seeing glass tanks inside the house. The acrylic feels good to the touch and very reassuring that it won't break easily even if it falls to the ground. I can even lift the whole tank with water and the contents inside.

Another amazing thing about this product is the rounded corners. They are a very good way to protect the tank against overly energetic kids and pets. This feature also adds aesthetic value which I find very pleasing to the eyes.

Meanwhile, the tank can accommodate freshwater and saltwater. I don't see any hard water buildup on the acrylic surface whenever I'm cleaning it. Similarly, I don't see any salt buildup on any corners of the tank during maintenance periods. Very easy to set up and maintain, it doesn't take too much time during cleaning. This really is a good tank for busy people.

The LED light is also commendable. It is housed in a canopy that can be moved through a hinge. I really like how the cover easily moves and prevents the fish and snails from escaping the tank. It is also a good way to prevent unwanted objects from entering the tank which could be mistaken for fish food.

While this aquarium kit is truly amazing, there is one thing that I don't like. It's how it lacks steady support for the bottom. Whenever I'm lifting this acrylic tank, I always use makeshift support made from a discarded 2-inch laminated board. This way, the bottom won't sag and spill the water out of the tank.

  • Lightweight
  • Durable
  • The front corners are curved
  • Ideal for freshwater and saltwater fish
  • Has an integrated LED light within the canopy
  • No steady support for the bottom included in the package
Upon consideration of all the important information about the aquarium kit, I can safely say that the SeaClear Acrylic Aquarium Combo Set is an amazing product. It is lightweight, made from durable acrylic, and has eye-pleasing curved corners. The LED light is truly amazing; it illuminates the contents of the tank and most of all – it doesn't hurt the eyes. If you want to try an acrylic tank, this product will surely satisfy you to no end.

Outdated Products

Marineland AMLPFK20B Biowheel Aquarium Kit (Outdated)


Providing the ideal setting for fish and plants is a must if you want to become a fishkeeper. This is what the Marineland (Aquaria) AMLPFK20B Biowheel Aquarium Kit aims to accomplish. If you want to succeed in your fishkeeping endeavors, the top-rated tank kit that you should have is definitely this one.

What I appreciate about this 20 gallon fish tank starter kit is the scratch-proof tank. With this, I am confident that sharp and pointy objects won't damage the surface of the glass which could lead to other untold incidents. Another thing that I truly applaud is its lightweight feature. Even my twelve-year-old child can carry it without breaking a sweat.

Another feature that I like is the LED lighting. It illuminates the contents of the tank properly. In addition, its glow provides an additional decorative effect on any space where the tank is installed. Meanwhile, the filter provides a phenomenal job of keeping the water clean and clear all the time. Its three-stage filtration system is truly remarkable. It keeps harmful organisms, harsh chemicals, and floating particles away from the water.

While the glass tank is scratch-proof, it is not entirely durable, which I find very disappointing. I had accidentally broken it when I gave it a little push. The water spilled all over the floor of my living room.

  • Has a scratch-proof tank
  • Lightweight
  • Has an efficient filter
  • Has eye-pleasing LED lights
  • Comes with a heater, water conditioner, fishnet, and fish food
  • The glass is not as sturdy as advertised
After carefully reviewing all the pertinent details about this product, I can conclude that this aquarium kit is one of the top-tier in the market. All the important accessories that you need for a 20 gallon aquarium are here: the tank, filter, heater, LED lighting, water conditioner, fishnet, and fish food. If you want to kickstart your fishkeeping hobby, this is the perfect product that you should try.

Elive Aqua Duo 20 Gallon LED Kit (Outdated)


The idea of recycling the dirt filtered out from the water to be used by a plant is part of a wonderful concept called aquaponics. Imagine your tank filter giving important nutrition to your precious plant. If you are into aquaponics, you will certainly love the Elive Aqua Duo 20 Gallon Aquarium Starter Kit.

There are so many things that I like about this aquarium kit. First is the magnificent LED light. It illuminates the tank magnificently. It brings a whole new level of beauty to the aquarium that not only I appreciate, but the guests as well. This tank becomes a wonderful piece of decoration at night.

Another phenomenal feature of this aquarium kit is the filter. I have to say; the filter is truly a work of art. It is designed to sustain important nutrients to a plant while delivering a top-notch performance of maintaining cleanliness inside the tank. Although I admit that I'm entirely new to aquaponics, this aquarium kit really made me interested in pursuing it.

The other freebies included in the package that I find really nice are the fishnet, the media bag, and the free Hydrocorn. With this plant, I can grow a plant using the free-floating elements in the water that are considered waste will be feeding the plant on top of the tank.

What I find very disheartening is the fact that this product cannot be easily ordered in any store. It took me a while to track down this particular aquarium kit being sold online (Amazon should always be the first place anyone should look). I guess aquaponics is still trying to make its way into the mainstream market.

  • Has an excellent filter made for aquaponics
  • Has a sturdy tank
  • Has an integrated LED light
  • Includes a hydrocorn
  • Includes a media bag
  • Includes a free fishnet
  • Hard to find in stores
All things considered, I must say that the Elive Aqua Duo 20 Gallon LED Kit Aquarium Starter Kits is a phenomenal product. It allows you to keep your fish in top condition while nourishing a plant at the same time. All the accessories included in the package are geared to help the user understand the concept of aquaponics. If you are interested in this kind of aquarium setup, then this is the perfect product that you should buy.

Aq Ascent LED Kit (Outdated)


Are you looking for a dependable 20 gallon tank to add to your collection? The Aq Ascent LED Kit 20g will provide your fish with the most suitable fish-keeping experience.

I love so many things about this particular aquarium kit. First is how organized the LED’s wiring is. The manufacturers really thought about the safety of the fish tank owners. If the wires were not as organized like this, it could certainly get exposed to the water and cause an untold possibility of an accident.

Speaking of LEDs, I love the way the canopy opens up like a hatch. It functions as a cover to prevent the fish from jumping out of the tank, and stop foreign objects from mixing with the water. I could open it to feed the fish without exerting too much effort.

Another feature that I really like is the contoured corners. Aside from keeping the children safe against accidents, it really accentuates the design of the aquarium. It makes the whole tank interesting to look at.

The last thing is the completeness of the package. It has everything a fishkeeper needs: free Premium fish food, a water conditioner, and a filter cartridge. This certainly frees me up with the monthly expenses of maintaining the fish.

What I don't appreciate about this product is how the LED lighting is not bright enough. Sure, it illuminates the contents of the tank but the overall decorative effect is not the same compared to other aquarium kits with LED light.

  • Has an LED lighting
  • Has a hinged LED canopy
  • The filter works quietly
  • The cords and wires are well-hidden
  • The corners are contoured
  • Easy to set up and clean
  • The tank's design easily captures attention
  • Has a free fish food, water conditioner, and filter cartridge
  • The lighting is not bright enough
Taking all things into consideration, I believe that the Aq Ascent LED Kit 20g is an awesome aquarium kit. It has nice LED lighting, a hinged canopy, contoured corners, and a quiet filter. Furthermore, the package includes fish food, a water conditioner, and a filter cartridge. If you are searching for a good tank kit for your aquatic pets, this one will give you the satisfaction that you need.

Aquarium Masters 20 Gallon Long Aquarium (Outdated)


If you have fish for breeding or simply for isolation, you need a reliable tank that can accommodate them properly. Surely enough, the Aquarium Masters 20 Gallon Long Aquarium starter kit will make sure that your fish are thriving.

I like that this 20 gallon tank is very durable. It is scratch-proof so I don't have to worry about my children's cats clawing its way to the tank. Also, the diamond-polished edges are good in ensuring my children's safety, especially when they are playing around the location of the tank.

Another thing that I like about this tank is the elongated shape. It provides extra space for my precious fish. It doesn't feel cramped at all. People will surely love to see the fish swimming around.

While I consider this 20 gallon tank awesome, there is one thing I wish the manufacturers included in the package. It is the cover. It could help fishkeepers like me keep the fish safe from escaping or prevent unwanted objects from reaching the water. I had to use a recycled plastic board to cover the tank.

  • Durable
  • Diamond-polished corners
  • The glass is distortion-free
  • Black-framed from bottom to top
  • No cover
In summation, I conclude that the Aquarium Masters 20 Gallon Long Aquarium is an excellent product. It is spacious, durable, and most of all, safe for children. The glass is made of quality materials. The black frame is also eye-pleasing.

Aqueon Deluxe LED Aquarium Kit (Outdated)


If your interest in fishkeeping has been suddenly switched on, you definitely need a good aquarium kit. The top-quality product to help you realize your dream is the Aqueon Deluxe LED Aquarium Kit Black 20 Gallon.

There are so many features of this product that I find wonderful. First, I'm glad that every accessory that an amateur hobbyist needs. This tank kit has LED lighting which helps me see the condition of the fish even during nighttime. The LED hood is perfect not only for housing the LED bulbs but also for keeping the safe fish inside. Furthermore, it also helps the light to be properly diffused inside the tank.

Another remarkable feature of this aquarium kit is the filter. It has a very reliable three-stage filtration system which keeps the water clean and clear at all times. What's good about this internal filter is it operates really quietly. I love how it maintains peace and quiet inside my home office. This is good for those people who have anxiety problems.

The water conditioner, fishnet, and fish food really help me save funds. I usually spend a hefty amount of money on fish food and maintenance. However, knowing that these freebies are actually included in the package, could definitely help me cut down my expenses and focus my budget on more important concerns.

What I don't appreciate about this tank kit is how the LEDs don't turn on immediately. I have to tap the hood once to brighten up the tank. Inasmuch as I want to fix this issue by checking the wiring, I'm afraid that it will only compromise the warranty.

  • Has an LED lighting
  • Has an LED hood
  • Filter works perfectly
  • Comes with fish food, fishnet, and water conditioner
  • The LED light doesn't turn on immediately
With all the important information thoroughly considered, I can safely say that Aqueon Deluxe LED Aquarium Kit Black 20 Gallon is a phenomenal product. It has every hobbyist’s needs: a filter, LED light and hood, fish food, fishnet, and water conditioner. The 20 gallon tank is very durable and aesthetically pleasing. If you are looking for a good tank to jumpstart your fishkeeping hobby, this is the product that you should consider.

What To Look For When Buying A 20 Gallon Fish Tank


With the 20 gallon tank's size, it is fairly easy to plan and set up a design or theme, just as it is quite versatile in the fish stocking.

With such potential in an average tank, how do you choose the right one for you? Here are some of the factors to consider when looking for the perfect 20 gallon tank for you.

Choosing The Right Dimensions

With a fish tank that is as versatile as the 20 gallon tank, there are sure to be some variations. The first one and probably the most common among the three is the 20 gallon long tank. With dimensions of 30 x 12 x 12, it is often chosen to be a reef tank because of its orientation. With loads of space for decorations, a theme that is meant to be wide can be highlighted with this 20 gallon tank.

Up next is the 20 gallon high tank, which is measured at 24 x 12 x 16. Its tall stand makes it beautiful for designs with a number of layers, for example, taller live plants. Lastly, there is the rarer 20 gallon EXTRA high tank, sitting at 20 x 10 x 24.

Choosing the right dimensions is important for two reasons. First, consider the direction and design, you might want to see in the tank. Will it fit your whole theme, will it highlight the theme's strengths? Second is the placement. The right variation of the 20 gallon tank will have you set your worries aside, in terms of the safety and stability of the tank.

Choosing The Right Placement

The dimensions of the tank are directly related to its placement. No one would want a tank to be a hindrance in a certain spot, not with the fragile parts and materials that the tanks come with. The 20 gallon tank shines in this area because of the delicate balance it presents; it is big enough to store multiple fishes and more ambitious set-ups, but yet small enough not to cause a massive placement problem.

The 20 gallon tank is a beautiful addition to any room, and it provides a certain kind of therapeutic view for everyone who chances upon it. As a longtime tank enthusiast, I have found that one of the most important factors to consider is the stand that holds the tank.

With quite a large amount of water in it, aside from the weight that is brought about by the materials, it is made of, alongside the fishes and the décor, the 20 gallon tank will prove to need a sturdier stand than those used for 15-gallon tanks.

While it will surely take up a small space in any room, it will not pose much of a problem than the bigger tanks. Just make sure that it is placed on a spot where the set-up's needed amount of heat, cold, and exposure is met.

Choosing The Right Materials

There are a number of pros and cons when it comes to choosing the perfect material when choosing your 20 gallon tank, and they are not to be overlooked.

The traditional 20 gallon tank is made of glass. Hobbyists from all over the world have known this variation for the longest time. It is durable, as it is not much affected by scratches. Its sturdy material results in less yellowing in the long run, however, it is also quite heavy and will be in need of reliable support.

There is also the acrylic 20 gallon tank, which has become more and more popular as time went by. The acrylic 20 gallon tank is visibly clearer and quite easy to clean. It is also easy to move around because of its lighter weight. However, it does not have the same scratch resistance as provided by the glass tank.

Both are safe for the tank and your little fishies, and both have decorations and equipment that support the material the aquarium is made of. Choosing the top-rated one for you relies on the placing spot you have, as well as the aesthetic visuals that you are planning for.

Ultimately, it relies on what kind of direction you would want to take in. Because of its size, its versatility can be seen in the set-up it creates, be it a community tank, a breeding tank, or even a hospital tank. Be sure to have a clear picture of your plans in your mind as you choose the right 20 gallon tank variation.

The Right Price For You

After evaluating every factor from dimensions, placement, and material, it is now time to think about the price. One great aspect of the 20 gallon tank is that it is an affordable tank, due to its popularity and size. The glass tanks are generally cheaper than their acrylic counterparts, but only by a smaller margin, unlike in the bigger tanks where variation costs may vary vastly.

As most of the 20 gallon tanks are sold as a package, complete with the lighting equipment, alongside the filters, heaters, coolers, and substrate, it can be a lot cheaper than other average-sized tanks. It also helps that it makes for an easier set-up process since all the equipment is already compatible with the tank's material.

Choosing the right price also relies on another factor: the warranty. The existence of a product warranty is a show of the brand's guarantee, and it can affect the pricing of the product itself. Will you opt for a one-time, cheaper buy for your tank or will you want to secure it for the long term? These are questions you should ask yourself before choosing the right tank for you.

Other Factors To Consider


What Is a 20 Gallon Aquarium?

The 20 gallon aquarium tank is among the most known aquarium types in the tank collecting hobby. Known for the versatility and flexibility the size provides, it is sought after by beginners and seasoned hobbyists alike.

For beginners, it is a great first tank to start up your collection. The general rule in this scene is that the bigger the tank, the easier it is to clean. Some newcomers might think otherwise because of the space it provides, however, the smaller the tank, the easier for the build-up to fill it. The visibility of the buildup that occurs in the smaller tanks is highly noticeable, which means the responsibility of cleaning it comes up more frequently for owners.

With a 20 gallon fish tank kit, you are safe from such rigid responsibilities, since the nitrogen cycle that occurs from inside the tank has much more space to operate on, leaving a safe allowance for you.

The 20 gallon tank is also quite famous for the storage space it provides. Being a tank of the average size, those who are transitioning from nano fish tanks can observe the looseness that comes with the tanks from the average range.

Unlike in the nano fish tanks where the fish stocking options might seem limited, the 20 gallon tank can hold varieties of fish. There is a general rule in tank collecting with regard to fish stocking, where you are allowed an inch of fish for every water gallon you have in the tank. Following this, the 20 gallon tank provides better space and freedom for budding enthusiasts.

Aside from having a great storage capability, the size of the 20 gallon tank is also quite flexible in a way. Because of its middle ground size, it is not too big and not too small. Meaning the placement of the tank will cause less of a hassle than when finding a spot for the bigger tanks.

The size is enough not to be a hindrance, and at the same time, the cost of running the tank will also be lesser. The 20 gallon fish tank is flexible and affordable at the same time.

How Does It Work?

It's pretty simple really. A 20 gallon fish tank works by holding water, aqua equipment, water plants, and of course, fish! This will serve as your aquatic pet's home.

What are the different types of 20 gallon fish tanks?

There are two types of fish tanks based on material, and these are:

  • Glass tanks – Glass tanks are the traditional material of aquariums. In addition, it is more expensive as compared to an acrylic tank because it is more durable and can tolerate the pressure that 20 gallons of water exert. However, it can also get heavier as the glass gets thicker. But the good thing about glass tanks is that it will remain clear even after a very long time.
  • Acrylic tanks – If you want to keep fish but you are worried about your budget, acrylic tanks are the ones that you should aspire to have since it is cheaper compared to glass tanks. It is made of thin, lightweight, and clear plastic. However, it can turn yellow and opaque after a long time.

Why Do You Need A 20 Gallon Fish Tank?

There are a number of options for 20 gallon tanks in terms of fish stocking variations. As the size provides a unique opportunity to support a midsized bunch of little fish friends, it can serve many purposes. The 20 gallon tank is versatile enough to be a breeding tank, a capable community tank, and a spacious hospital tank for seasoned collectors. It is as well a great beginner fish tank for newcomers because of its affordability and size.

Frequently Asked Questions


What fish can go in a 20 gallon fresh water tank?

Freshwater tanks can house a vast amount of fish species. But if I have to recommend only a short list, the following fish would be excellent options:

  • Guppies
  • Angelfish
  • Goldfish
  • Mollies
  • Rainbowfish
  • Neon Tetra

But before selecting one of these fish, please look into its particular needs. You’ll want to prepare for everything when choosing a fish, especially if you’re a newbie. It’s the only way to ensure you’re fully equipped to be a competent owner.

How much does a 20-gallon tank cost?

Most 20-gallon tanks are available for sale anywhere between $20 and $120. Determining where a tank is more or less costly depends on its features and quality. For instance, an all-in-one tank with a glass construction will be more expensive than a standard acrylic option without any accompanying accessories.

As a result, buyers must account for these factors when selecting their 20-gallon tank. I’d suggest building a budget around those needs to make it easier. Trust me; it makes a world of difference, especially when making a comparison between tanks from top brands like Top Fin or Tetra.

Is it better to have 1 or 2 goldfish?

Goldfish are known for thriving better when they have a companion. They’re even known to school together, which promotes more exercise and better health. So it’s top-tier to have at least two goldfish rather than keeping only one.

But there’s no need to panic if you don’t feel comfortable getting two goldfish. If you properly maintain the creature tank, be it vertical or horizontal, a single goldfish can live a happy and normal life. Or you could select a more solitary species, such as a betta fish.

What are the most trusted 20 gallon fish tank brands?

  • Aqueon
  • Tetra
  • Marina
  • Marineland
  • Sea Clear
  • Aquarium Masters

How to set up and use?

Like any other fish tank, the process of setting up the 20 gallon fish tank can be long and tiresome, but its importance overshadows the complexity and intricacies involved.

Water Prepping – Set aside the 20 gallons of water that you are to use for the tank. It is important to place them in a container and a place where it is less likely to be disturbed or contaminated. It is important to let the water sit for two (2) to three (3) days in order for it to settle, and also to let the unwanted chemicals dissolve away.

Deciding on the Direction – While waiting for the water to be ready, take this time to plan out your tank and the direction you want to take with it. Once you have started out in a direction, you cannot just change it willy-nilly because setting up the tank is often for the long term, and the variable changes that might happen will have a tremendous effect on the whole tank.

Plan out the background and the general landscape theme you have in mind. It is also important by this time to choose the right substrate for your theme, and decide if you are planning to have additional elements to the tank, like live plants for example. This way you can leave a sort of allowance for the added elements.

After planning it out, you are now to place the substrate on the tank. Now the amount of substrate to be placed in the tank is entirely up to how thick you want it to be. However, the general ruling enthusiasts like to follow is 1lb of substrate for every gallon of water, which makes at least a 1†thick substrate for the tank. If you want it to be thicker, then you can opt for 2lbs of substrate for every gallon, which can make 2†of the gravel bed.

Priming – After the waters sit out for 2 – 3 days, you can put it in the tank. However, to test out the waters, seasoned hobbyists would like to test out about half of the water and put it on the tank, along with the other decors and equipment. This is the time to install and test out the water filter, the air pump, the lighting, and prime them. After the installation and the priming, you can now place the decorations and complete the tank's design.

Filling the Tank – Now comes the long part, filling the tank. While placing the water in the tank itself is fairly easy, letting it sit for a couple of weeks can be a grueling wait for some. However, patience is one of the key attributes of a fish tank collector, and as you will come to see as you grow in the hobby, it pays off in the long run.

Letting the water sit for a couple of weeks makes sure that unwanted chemicals in the water will dissolve, in turn making the water ready for supporting marine life. The process also ensures that the water is ready to break down the wastes that will come with the live elements of the tank, like fish, live plants, and invertebrates. This process is helped along by the biological media of your filter, as well as the placement of live plants.

How to care and clean?

If you have a good filtration system, chances are you wouldn't have to clean your aquarium as often. Cleaning up a tank should be done every two to four weeks, depending on your filtration system's effectiveness. Don't wait for your fish tank to cloud with waste before you clean it. Set a regular schedule.

The following are the steps to cleaning your tank:

  1. Turn off all the equipment and remove them carefully.
  2. Fill a container with some water from the tank. This is where you will place your fish while you clean the tank, so make sure there is enough water for them to swim around.
  3. Carefully move the fish to your temporary container.
  4. Remove most of the aquarium water.
  5. Remove the tank accessories. It's up to you if you want to remove the gravel too.
  6. Scrub the sides of the tank to remove waste and algae buildup.
  7. Run water through the tank to rinse the dirt away.
  8. Place your dechlorinated water into the tank. Don't fill it up to the brim as you still need to place the original aquarium water and fish in the tank.
  9. Put the fish and the aquarium equipment back.

Where to buy?

When looking for cool 20 gallon fish tanks, you can search in Petco, Home Depot, Walmart, or Petsmart. If you want to purchase one online, like I do most of the time, you can purchase one at Amazon. You do not need to leave the comforts of your home and you can get it by the next day.


The 20 gallon aquarium is a versatile tank that gives space for multiple stocking options, it also assures the owner of a more stable timeframe with regards to the cleanup, and it is versatile as well as affordable. You can place a lot of one-inch fish here, or a couple of big ones. If you want your aquarium to last for several years, you should get nothing but the best 20 gallon fish tank.