Fish tanks or aquariums can vary in size depending on the species that you are going to take care of. If you are a beginner at fish keeping, you may find a 20-gallon tank a bit too big, but for those who are of intermediate level, the 20-gallon tank is a good way to go. This is why you may be looking for the best 20 gallon fish tank.
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Many different fish species can fit into this tank (we’ll list them down below in this article), but we’d also like to suggest to you some good fish tanks you can buy for starters in this size. After all, you can’t have happy fish without a properly-fitting aquarium for their wants and needs!
Top 5 Best 20 Gallon Fish Tanks
If you are looking for a 20 gallon fish tank review, here are our top picks for the best 20-gallon fish tank in the market today:
Marina LED Aquarium Kit
This aquarium kit is made with quality glass and is easy to set up due to the clip-on filter, which doesn’t really get in the way when you place it anywhere. It is good for beginners due to including nearly everything you need to set up your aquarium at home.
With a size of 24 x 12 x 16 inches, this one also comes with its own set of LED lighting so you can set up a lighting system right away. Included in the set is also a water conditioner, which can be useful if you are keeping tropical fish. It also comes with its own user instructions to help you set it up.
Things We Liked
- The lighting is energy-efficient
- Good for beginners due to being a complete kit
- Comes with its own filter
- Includes a water conditioner
- Has a slim filter that’s easy to install
Things We Didn’t Like
- May have durability issues with the lighting
Tetra 20 Gallon Complete Aquarium Kit
If you want an aquarium kit that comes with good lighting, this one is also a decent choice. It has a quiet filter that comes along with it so you don’t disturb the people in your house when you’re running it. The set also comes with a plant mat so you can easily set up the plants and decor inside your aquarium. You can just add the substrate or gravel and the fish to complete the set.
The LED hood has a design that mimics the natural lighting of the bottom of the ocean. It also comes with various accessories, such as a thermometer to measure the tank water’s temperature – ideal if you want to keep specific fish, such as tropical fish.
Things We Liked
- Includes artificial plants and tank mat
- Has a good LED lighting
- Good for tropical fish with temperature needs
- Beginner-friendly tank
Things We Didn’t Like
- The filter may not be that quiet for some people
Aquarium Masters 20 Gallon Long Aquarium
If you intend to keep more than just fish, you can find this long aquarium quite useful due to its design. It has a distortion-free glass, which can help you to easily see what’s inside. The size of the whole thing is 30 x 12 x 12 inches and it can also be used by both tropical and marine fish.
Because of the combination of the silicone sealant and the black frame, it can help prevent leakage from inside the fish tank. It can also fit different kinds of lighting setups.
Things We Liked
- Easy to clean
- Distortion-free glass
- Can be used for both tropical and marine fish
- Nearly leak-proof black frame and sealant
- Fits most lighting setups
Things We Didn’t Like
- No lit included
Innovative Marine Nuvo Fusion PRO 20 Gallon AIO
Including most accessories, such as a return pump, filter sock, mesh screen cover, and others, this one can also be a good beginner’s kit as a 20-gallon tank. It measures 24 x 15 x 13 inches and it uses a low iron and high clarity glass with a thickness of 6mm. Its included return pump flows up to 326 GPH so it’s pretty good for most fish sizes.
There is also a rubber leveling mat included with the tank and you don’t need to install it since it’s already there. The mesh screen cover is also installed in the unit when it arrives.
Things We Liked
- Low-iron glass for clarity
- Includes a return pump
- Pre-installed mat
- Includes a magnetic glass cleaner
- The included pump is quiet
Things We Didn’t Like
- Doesn’t include lighting
Seapora 59201 Standard Extra High Aquarium
If you don’t have a lot of room at home for an aquarium that lays horizontally, you can opt for this one, which has a vertical design. It uses black silicone on the sides to keep it leak-proof when you fill it up with water and fish. Since it is also made with injection molding, it can hold up pretty good.
The measurement for this aquarium is 20 x 10 x 24 so it can possibly fit most small spaces. The edges have been polished by diamonds so it can look elegant for most rooms.
Things We Liked
- Good quality frame
- Unique vertical design
- Fits most tall plants
- Has an elegant design due to the diamond polishing
Things We Didn’t Like
- Doesn’t come with a lid
Things to Consider
Before you buy a 20 gallon aquarium, you may want to look at the following facts first:
What are the basic things you need for a 20-gallon tank?
If you are a beginner at setting up a fish tank, here are the things you may need to get started:
- Tank filter. You need a filter to circulate the water and make sure that the fish don’t get intoxicated by their own ammonia. Most 20-gallon tanks use a hang-on back filter due to their ease of placement.
- Water heater. In cases when you need your fish to be in a specific temperature (or your plants, for that matter), you may want to buy a water heater with a thermometer.
- Lighting. The lighting system can be important for both fish and plants, as it can stimulate growth for the plants and can also provide a warm and welcoming environment for the fish. Choose LED lighting to make it more energy-efficient.
- Substrate. The substrate is going to be your bottom part of the aquarium, which can be gravel, sand, or both. Keep in mind that different plants work well with different substrates, so choose carefully.
- Plants. As we mentioned above, plants are important to mimic the natural environment of the fish. It’s a good idea to know which plants grow just fine on a 20-gallon tank.
Which fish species fit best in a 20-gallon tank?
You may want to consider the following species if you haven’t decided on a 20-gallon tank yet and want to choose a fish species:
- Harlequin
– Ideal number: 6 in a school
The harlequin rasbora is fish that are colorful and vibrant. They may remind you of Joker’s trusty sidekick due to the color combination. They are best in 20-gallon tanks but they don’t do too well with large fish since they can be prey.
- Otos
– Ideal number: 6 to 8 in a school
The otocinclus is great for when you want to have no algae eaters in your tank and your tank gets algae all the time (or more often than usual). Instead of having to scrub your algae-infested tank, go for these little guys instead.
- Guppies
– Ideal number: 2:1 ratio for female and male
Since guppies multiply like rabbits, they should be narrowed down in terms of the population if you don’t want your tank to be too cloudy all the time. They are great for beginners, however, since they can be easy to feed and take care of. They tend to have bright designs on their scales.
- Zebrafish
– Ideal number: 6 in a school
If you want a fun and active fish, go for the zebrafish. They are similar tetras and they can be great for those who are new to fish keeping. They have a stripe on their scales to mimic the appearance of zebras.
- Neon tetra
– Ideal number: 6 in a school
You can definitely count on the neon tetras, since they are also beginner-friendly and you can even keep more than 6 in a school, as long as they are the only species in the aquarium, since they tend to be not too friendly with others not of their kind. They tend to have a bright orange design.
- Dwarf gourami
– Ideal number: only 1 male per tank
The dwarf gourami may be prone to bullying other fish so it’s a good idea to just keep one male in one tank to avoid such scenarios. You can also put up good hiding spots, such as large live plants and the like.
- Cory catfish
– Ideal number: 6 or more in a school
The cory catfish are best with different varieties of the species so that you can have a colorful set. They tend to be bottom swimmers so they may catch most of your sinkers. They will also do well in a 10-gallon tank.
- Molly fish
– Ideal number: 6 or more
The molly fish can multiply fast as well since they are livebearers. You may find the black molly especially pleasing but there are also other molly fish species out there.
- Swordtail
– Ideal number: 2:1 for female and male ratio
The swordtails can be cool, colorful, and unique, but they could be quite aggressive at times as well, so it’s best to have fewer males. They are best known for their sword-like tails.
- Platies
Ideal number: 2:1 for female and male ratio
Like the swordtails, the active platy is a highly energetic fish species that could be prone to bullying and aggressiveness. They tend to have a Mickey Mouse shape on their tails.
Which plants work best on a 20-gallon tank?
Most plants that are good for low-light conditions can work for this size of the tank. If you want to keep a 20-gallon tank and fill it up with live plants, you can go for the following suggestions:
- Amazon swords
- Anubias
- Java moss
- Crypts
- Hornwort
Can I also put snails and shrimp in a 20-gallon tank?
Yes! You will find it beneficial to put snails and shrimp in tanks since they can eat up most of the algae and other small food items that your other fish may not need. They can be great for balancing the ecosystem inside your fish tank setup.
How do I select fish for the tank?
There can be some criteria for choosing specific fish in your tank, such as:
- How many fish? Some fish are okay to be kept in many numbers while others are best trimmed down.
- Gender of the fish? Some fish reproduce a lot or bully each other so keeping the gender ratio is important.
- Bottom, middle, or top swimmers? Don’t put all top swimmers so they won’t bump into each other – consider a little bit of each type.
- Aggressive or peaceful? Don’t put together fish that may not be good with other species. Some of them can be aggressive.
- Saltwater or freshwater? You should also consider whether you want to keep saltwater fish or freshwater ones in general (this has an effect on your temperature maintenance).
Conclusion
To wrap it up, our top pick is the Marina LED Aquarium Kit due to its energy-efficient LED lighting, the inclusion of a clip-on filter, ease of installation and setup, good size, and the inclusion of different fish keeping supplies to get you started. While others are okay for being a 20-gallon tank, this one is generally better due to its beginner-friendly package and friendly user instructions to help you get started on fish keeping.