Updated: February 2, 2021 - By: - Categories: Equipment, Starter guide

A twenty-gallon aquarium is a perfect sized tank for those wishing to start keeping tropical fish, it is large enough for a small community (depending on the species you wish to keep) and is also ideal as a quarantine or hospital tank.

Best 20-gallon fish tanks and kits

Let’s take a look at some of the 20-gallon aquariums available to buy, we’ll talk through the features of each one so that you can best decide which one will suit you best.

Model Our rating Aquarium tank Dimensions Hood & lighting Filtration Heater & thermometer Others
Marina LED Aquarium Kit editor's ratingMarina LED Aquarium Kit 20-gallon glass, best for starters 24″ L x 12.5″ W x 16.5″ H Hood with LED lighting Marina Slim S20 clip-on filter with cartridges not included Fish food, supplement, conditioner, fish net, thermometer, and guide
Aqueon LED Aquarium Kit 20H Black editor's ratingAqueon LED Aquarium Kit 20H Black 20-gallon glass, high form 24.25″ L x 12.5″ W x 16.75″ H Hood with LED lighting QuietFlow 10 power filter with medium cartridge 100W preset heater at 78 degrees premium fish food, water conditioner, fish net, stick-on thermometer
Tetra Aquarium 20 Gallon Fish Tank Kit editor's ratingTetra Aquarium 20 Gallon Fish Tank Kit 20-gallon glass 24.2″ L x 12.4″ W x 16.7″ H LED hood Tetra Whisper 20 HOB filter Tetra mini UL preset heater 1 artificial Boxwood Plant Mat, 4 artificial plants.
Aqueon Aquarium 20 Gallon Long editor's ratingAqueon Aquarium 20 Gallon Long 20-gallon long glass, blank without equipment 30.25″ x 12.5″ x 12.75″
GloFish Aquarium Kit editor's ratingGloFish Aquarium Kit 20-gallon glass tank for Glofish 24.2″ L x 12.5″ W x 16.2″ H Hood with 13″ blue LED light stick for GloFish Tetra Whisper 20 HOB filter Tetra mini UL preset heater for tropical fish decorations, fish food, conditioner, and guide.
SeaClear Acrylic Aquarium Combo Set editor's ratingSeaClear Acrylic Aquarium Combo Set 20-GAL acrylic rectangular, blue backdrop 24″ L x 13″ W x 16″ H Hood with 15″ light reflector (bulb not included)
SeaClear Acrylic Hexagon Aquarium editor's ratingSeaClear Acrylic Hexagon Aquarium 20-GAL acrylic hexagon, black backdrop 15″ x 15″ x 24″ H Hood with 12″ light reflector (bulb not included)
Tetra ColorFusion 20 Gallon Fish Tank Kit editor's ratingTetra ColorFusion 20 Gallon Fish Tank Kit 20-gallon glass 24.2″ L x 12.4″ W x 16.7″ H Hood with color-changing LED light Tetra Whisper 20 HOB filter Tetra mini UL preset heater decorations, fish food, fish net, digital thermometer, conditioner, and guide.
Landen Rimless Low Iron Aquarium editor's ratingLanden Rimless Low Iron Aquarium 17.1-gallon rimless glass, blank 23.6″ L × 11.8″ W × 14.2″ H
SC 24 Gallon All in One Aquarium editor's ratingSC 24 Gallon All in One Aquarium 24-gallon glass 24″ L x 15″ W x 15″ H back-panel filtration return pump, and plumbing kit

20 gallon aquarium reviews

Marina LED Aquarium Kit 20-gallon

The Marina LED Aquarium Kit is an ideal tank for a beginner interested in keeping fish. It comes with most things you will need for the setup process. They include a rimmed glass tank with LED hood, Marina Slim clip-on filter with cartridges, water conditioner (to treat tap water), tropical flakes, biological supplement (to boost the Nitrogen cycle), fish net, stick-on thermometer, and care guide.

What I love best in this kit is its filter with quick-change cartridges. The cartridges are floss pads included with activated carbon and ceramic to perform three-stage filtration with mechanical, biological, and chemical. It is very efficient in keeping the water clean, clear, and free of Nitrogenous toxics.

The LED lighting, which is housed within the hood, is energy-efficient so the running cost is reduced; this white LED lighting is also suited for live plants if you wish to keep some within the tank.

It is a complete setup if you wish to house coldwater fish. It doesn’t come with a heater, simply add a 100-watt heater and you can then keep tropical livestock.

Aqueon LED Aquarium Kit 20 Gallon

This 20-gallon tank is ideal for those wishing a full set-up. Within this product, you’ll find most items needed to keep freshwater tropical fish. There are a QuietFlow 10 PRO power filter, 100W heater, fish food, water conditioner, fish net, and a thermometer.

The main tank is a standard shape and comes with a black lid. The black hood consists of a feeding hatch and LED lighting.

The filter is a hang-on one that is perfectly sized for this tank. It is able to alert you, with a red light, when its cartridge needs to be replaced (one included).

The heater is a preset one and holds a temperature of 78 degrees; so, ensure any livestock kept in this aquarium that requires heat is suited to this exact temperature if you intend on using this heater.

Tetra Aquarium 20 Gallon Fish Tank Kit

This aquarium starter kit is 20-gallons and an ideal set-up for those starting in aquarium keeping.

It is a beautiful tank, classically shaped, and comes with everything needed to get you started. Its edges are well sealed with clear silicone, and the base and top are reinforced with black rims for durability and a longer lifetime.

The kit comes with an LED hood, Tetra Whisper 20 Hang-On-Back filter, preset heater, and some decorations. The LED lighting unit is energy efficient and is designed to mimic natural sunlight.

If purchasing this starter tank, you’ll also gain access to Tetra Care, which provides you with free help and advice in running an aquarium.

Aqueon 20 Gallon Long Aquarium

This 20-gallon tank is suitable for both freshwater and marine setups. It is a long tank that means it provides more contacting space between the surface water and the air, compared to a high/standard form. This makes it better for stocking fish.

This longer sized tank is suitable for species that prefer swimming space on the surface like Zebra Danios, Guppies,… It is also ideal if you plan to keep bottom-dwellers; such as small Corydoras, shrimp, or catfish, so they have more area to roam about in.

It comes as a blank glass tank only without any equipment. So, you will need to add your own lid, filter, heater, lighting, etc., depending on what you decide to house in it.

GloFish Aquarium Kit Fish Tank

This tank makes a great choice for any Glofish keeper. It is 20-gallons and comes with most extras needed to start a tropical freshwater set-up.

Included in this kit are a hood with LED lighting, Tetra Mini UL Heater, Tetra Whisper 20 filter, GloFish yellow anemone, 2 x plant multipacks, fish food, water conditioner sample, and a care guide. This offers amazing value; simply add substrate and livestock and you’re good to go!

The blue LED lighting that this tank provides looks amazing if you have Glofish within the tank; you can also purchase numerous GloFish accessories to jazz the aquarium up further if required.

This tank set-up is one of the better options if you’re wanting a complete set-up and intend to keep Glofish.

SeaClear Acrylic Aquarium Combo Set – Rectangle

This SeaClear aquarium is 20-gallon and made of high-quality acrylic. It comes as a blank tank with a hood and blue backdrop, and without other necessary supplies. It can be used for either freshwater or marine fish.

The clear acrylic top of the tank is pre-drilled with hoses for fitting the lid, a Hang-On-Back filter (not included), and a heater (not included).

The hood with its 15″ fluorescent light fixture is junk when most home aquariums these days use modern LED lights. However, there are no more available options to go for an acrylic aquarium with a medium volume of 20 gallons and you have to buy it if you prefer acrylic to glass.

I will show you the way to make it perfect with only small and easy customization. Just throw the lid away, then buy a 24-inch LED light fixture with extendable brackets and hang it on the acrylic top. Luckily, the top is flat to do so. It is also clear for light to penetrate through. Setting up in this way, the acrylic top will also protect the LED light fixture from damages from the aquarium water, and thus prolonging its lifespan.

SeaClear Acrylic Aquarium Combo Set – Hexagon

This 20-gallon aquarium is the same as the previous but it is a hexagonal one; for something that little bit different. It offers a unique shape and very clear viewing areas.

Like the previous, you will also make some customization for this tank to make it perfect. And you will need a 15-inch LED light fixture to fit on its top. You will also need to buy a filter and heater for setting it up. You can find these in the following sections in this article.

Tetra ColorFusion Aquarium

This 20-gallon tank is a beautiful complete set-up that would make an ideal first tank or a second smaller tank.

Scratch-resistant glass is used here, and the tank itself comes with a lifetime warranty. Also included are an LED hood, Tetra Whisper filter, Tetra HT 20 heater, water conditioner sample, digital thermometer, fish net, care guide, and some decorations. You have everything ready to go, simply add your choice of substrate.

The special feature of this product is its color fusion LED lighting. It allows you to opt from several color choices, each designed to show off the best colors of the fish housed within the tank. This is one of the best options for those looking for a 20-gallon tank combo.

Landen Rimless Low Iron Aquarium Tank

This tank is slightly under 20-gallons, it will hold 17.1 gallons, and is constructed from heavy-duty 6mm glass. This glass is low-iron and offers very clear viewing. This is an ideal purchase for those who are finding a rimless tank to build an attractive planted aquascape.

If you’re looking for a basic tank that you can customize as you prefer; with your heater, lighting, etc. then this is one of the best options available. You get a strong, sturdy tank that you can set up exactly as you wish to.

SC Aquariums 24 Gallon All in One Reef Aquarium

This tank is slightly larger than most on the list and will hold 24 gallons. The aquarium is made from Starfire/low iron glass, which makes for beautiful transparency for viewing.

Three behind compartmentsThree behind compartments

It is specially designed with a built-in rear chamber overflow with three compartments for housing filter materials, a pump, and other equipment. This design hides all equipment from view leaving the tank with nothing more than an attractive aquascape with colorful fish.

The way it works is so easy to imagine; the pump pumps the water from the rear chamber to the main view tank, the overflow water from the main tank flows to the chamber containing filter materials through its drilled hoses for continuous filtration, and then returns to the tank with the pump.

You can use it for either a marine or freshwater setup. However, most aquarists built it as a nano reef because the back panel provides an ideal place to install a small protein skimmer. You will need to buy a reef tank LED light to fulfill the setup. I strongly recommend the Nicrew HyperReef 50 for the tank.

Accessories and replacements

Most twenty-gallon tanks will be sized as follows, give or take a small amount; for standard shaped tanks (24″ x 12.5″ x 16.5″) and long shaped tanks (30″ x 12.5″ x 12.5″) and will weigh around 220 lbs when filled. This allows you some ideas of what equipment can fit into the tanks.

Canopy

H2Pro 24-inch glass canopy, 23.07 x 11.69 x 0.16inH2Pro 24-inch glass canopy, 23.07 x 11.69 x 0.16in

H2Pro 30-inch glass canopy, 29.21 x 11.69 x 0.16inH2Pro 30-inch glass canopy, 29.21 x 11.69 x 0.16in

Not all aquariums come with lids as standard so you may need to add one. To find the best one for your tank, ensure you measure up correctly and check against the dimensions of the lid you intend to buy.

Stand

Most 20-gallon aquariums do not come with a stand and it is advisable to use an aquarium stand as these are designed to hold the weight of the tank when filled with water. To choose the best stand you’d like then ensure the length and width of the tank itself match the stand and that the stand is suitable for holding the required weight.

Find a stand here: https://portlandaquarium.net/fish-tank-stand/

Lighting

Most aquariums do come with lighting but if yours does not, or you wish to change the lighting unit to something different then you need to make sure that you choose a light that is suited to your aquarium.

You should make sure that the light is suitable for the length of your tank, and whether it is suited to plants and/or corals if you keep either of those. Not all lights are a fit-all solution and some are more specialized than others. You will need a 24-30 inch LED light for a 20-gallon tank.

Filtration

Filtration is the most important thing to get correct when keeping an aquarium, they help to keep your water in peak condition for any livestock you keep.

When choosing a filter, you need to get one that is capable of turning over the volume of water in your tank 4 times per hour. That means in a 20-gallon aquarium you need one that turns over 80 GPH (gallons per hour).

Heater

If you intend on keeping tropical fish then a heater is a must-have item in the tank. Not all aquarium setups come with one included. If you’d like to add one then you need to ensure the one you put in the tank is suited to its size and can hold the temperature required.

As a basic rule of thumb, 1W is required per liter of water (or 3.8W/Gal), so for a 20-gallon tank, we’d advise a heater that is 75-100 watts.

Substrate

Spectrastone Shallow Creek RegularSpectrastone Shallow Creek Regular

How much substrate will you need? A pound per gallon is a good rule-of-thumb to have a 1-inch substrate. This means you will need at least 20 pounds of substrate for a 20 gallon tank.

For fish-only tanks, the substrate thickness depends on your preferences but ensure it is no thinner than 1 inch. Just go with medium-sized gravels for easy cleaning.

For planted tanks, you will need a thicker substrate for the growth of the root system, 2-3 inches is recommended. You will also need a special substrate for planted aquariums that can nourish the plants.

Background

Vepotek aquarium background, double sides for choiceVepotek aquarium background, double sides for choice

Many people like to use an aquarium background in their tanks, it adds imagery and depth to an aquarium and there’s an abundance of patterns and pictures to choose from.

To select the correct one, ensure you measure the total length and height of the tank and match it to the background you purchase. It is advisable to purchase a little bigger if you can not find the correct size, you can always trim it (carefully) to fit.

Air pump

Uniclife Adjustable Air Pump 2 L/minUniclife Adjustable Air Pump 2 L/min

An air pump isn’t a necessity in an aquarium with filtration but many people opt to include one, or more, within their tanks. Air pumps are usually used to operate some action aquarium decorations and air-driven filters such as undergravel, sponge, and corner box filters.

The benefit of an air pump is that it helps aerate the water, which in turn provides more oxygen to the aquarium water which is beneficial to livestock within.

For a 20-gallon aquarium, you need to look for one that has a minimum output of 0.660 liters/min. This also depends on how much equipment needs to be powered with the air pump and how deep your tank is.

If you keep a marine aquarium you will need a stronger one, owing to the fact saltwater has 20% less oxygen solubility than freshwater.

Water pump

A water pump is a great addition to an aquarium to create a flow within the tank. This helps to keep water fresh and also some fish benefit from stronger flows which they enjoy swimming in. You can also use a water pump to help with water changes.

When looking for a water pump you should get one that rotates the volume of water in your tank 5 times per hour. This means for a 20-gallon tank you’d need a minimum rate of 100 GPH to ensure the best efficiency.

Decoration

There are so many decoration options when it comes to an aquarium. You can have ornamental ones; from sunken ships, bridges, mountains, etc. to artificial plants, driftwood, caves.

You should consider the fish you intend to keep when planning your décor as some prefer having hiding spots so you can match their needs to your preference for décor.

How many fish for a 20-gallon tank?

The amount of fish you can keep depends on the size of your tank and the size of the fish you keep. You can keep 1 inch of fish per gallon, based on the size of the fish when fully grown. E.g. You can keep 20 fish that maxes at 1 inch when fully grown.

When choosing fish for an aquarium, ensure all the species have similar water requirements so that you can set up the most optimal water environment for them. You should choose many species that handle at different levels of the water column to form a small community.

200+ brackish and freshwater species for 20-gallon tanks

Family Scientific name Common name Max length Special notes Temperature pH Water hardness (dGH)
Brackish Brachygobius xanthozonus Bumblebee goby 2.0 inch territorial towards others of its own species 71.6 – 82.4°F 7.5 – 8.5 11.2 – 19.6. Salinity: 2 – 10%
Brackish Hypseleotris compressa Empire Gudgeon 4.7 inch eat smaller fish that fit in its mouth 68.0 – 86.0°F 7 – 8.5 15 – 30
Brackish Pseudambassis ranga Indian glass perch, Indian glass fish, Glass fish 2.0 inch 68.0 – 78.8°F 7.3 – 7.5 8.4 – 14. Salinity: 1 – 20%
Brackish Stigmatogobius sadanundio Knight Goby, Fan Dance Goby 3.5 inch territorial towards conspecifics 68.0 – 78.8°F 7 – 8.5 10 – 20. Salinity: 0.35 – 0.7oz salt/ 2.6 gallons
Catfish Ancistrus cirrhosus Common Bristlenose Catfish, Jumbie teta 4.9 inch 71.6 – 80.6°F 5.8 – 7.5 1 – 15
Catfish Auchenipterichthys coracoideus Zamora Woodcat, Midnight Catfish 3.5 – 4.3 inch 71.6 – 77.0°F 6 – 7.2 0 – 10
Catfish Centromochlus perugiae Oil Catfish, Oil Woodcatfish, Perugia’s Woodcat 2.4 inch 75.2 – 86.0°F 6 – 7 1 – 25
Catfish Chaca chaca Frogmouth catfish 7.9 inch species tank 71.6 – 77.0°F 6 – 8 4 – 25
Catfish Corydoras aeneus Bronze catfish, Bronze corydoras 2.6 – 3.0 inch 68.0 – 80.6°F 6.5 – 7.5 1 – 20
Catfish Corydoras arcuatus Skunk Cory, Arched Cory 1.8 – 2.2 inch 71.6 – 78.8°F 6 – 8 2 – 25
Catfish Corydoras axelrodi Pink corydoras, Axelrod’s Corydoras 2.0 inch 68.0 – 73.4°F 6 – 7 1 – 15
Catfish Corydoras duplicareus Saddle Corydoras, False adolfoi cory 2.0 inch 71.6 – 78.8°F 6 – 7 1 – 15
Catfish Corydoras eques Horsemans Cory 1.6 – 2.0 inch 71.6 – 78.8°F 6 – 8 2 – 16
Catfish Corydoras haraldschultzi Harald Schultz’s Cory, Mosiac Cory 2.8 – 3.3 inch 75.2 – 78.8°F 6 – 7.2 2 – 15
Catfish Corydoras julii Julii Cory, Leopard Cat, Leopard Cory 2.2 inch 73.4 – 78.8°F 6 – 7.2 2 – 15
Catfish Corydoras melanistius Black-spotted corydoras, Melanistius catfish, Bluespotted corydoras, Blacksail corydoras 2.4 inch 68.0 – 82.4°F 5.8 – 7.5 2 – 20
Catfish Corydoras melini False bandit cory 2.0 inch 71.6 – 78.8°F 6 – 7 1 – 15
Catfish Corydoras metae Bandit Cory, Masked Cory 2.0 inch 71.6 – 78.8°F 6.5 – 7.5 2 – 15
Catfish Corydoras nanus Mini Cory, Nanus Cory Cat 2.0 – 2.4 inch 71.6 – 78.8°F 6 – 8 2 – 25
Catfish Corydoras paleatus Marbled Corydoras, Peppered corydoras 2.4 – 3.1 inch 69.8 – 80.6°F 6 – 8 2 – 28
Catfish Corydoras panda Panda Catfish, Panda Cory 1.6 – 2.0 inch 71.6 – 82.4°F 5.8 – 7.8 2 – 20
Catfish Corydoras schwartzi Schwartz’s Cory 2.0 – 2.4 inch 71.6 – 78.8°F 6 – 7.5 4 – 19
Catfish Corydoras similis Smudge Spot Cory 2.0 inch 69.8 – 80.6°F 5.6 – 7 1 – 15
Catfish Corydoras sterbai Sterba’s Cory 2.6 inch 78.8 – 86.0°F 6 – 7.6 10 – 15
Catfish Corydoras trilineatus Leopard catfish, Three line cory 2.4 inch 71.6 – 78.8°F 6 – 7.2 2.2 – 14
Catfish Corydoras zygatus Black band catfish 2.4 – 2.8 inch 71.6 – 78.8°F 6 – 7 1 – 15
Catfish Dianema longibarbis Porthole Catfish 3.9 inch 75.2 – 82.4°F 5.5 – 7.5 1 – 20
Catfish Dianema urostriatum Flag-Tailed Catfish, Flagtail Catfish, Flagtail Porthole Catfish 4.9 inch 77.0 – 82.4°F 6 – 8 5 – 20
Catfish Hemiodontichthys acipenserinus Knobnose Whiptail Catfish, Pinocchio Whiptail Catfish 5.3 inch 75.2 – 82.4°F 6 – 7 2 – 12
Catfish Hypancistrus inspector Snowball Pleco 4.9 – 6.3 inch 71.6 – 86.0°F 5.4 – 7.6 1 – 15
Catfish Kryptopterus macrocephalus Striped glass catfish 3.5 – 3.9 inch 71.6 – 80.6°F 4 – 7 0 – 10
Catfish Microglanis iheringi South Amrican Bumblebee Catfish 2.0 – 2.8 inch 69.8 – 78.8°F 6.5 – 7.5 10 – 18
Catfish Panaqolus maccus Clown Pleco, Ringlet Pleco, L-104 catfish, L-162 catfish 3.9 inch peaceful, a little territorial 71.6 – 86.0°F 5.5 – 7.5 7 – 20
Catfish Rineloricaria lanceolata Chocolate-colored catfish 3.5 – 3.9 inch 77.0 – 82.4°F 6 – 8 5 – 20
Catfish Rineloricaria microlepidogaster Whiptail catfish 4.7 – 5.5 inch, In nature it can reach up to 9.8 inch 69.8 – 82.4°F 6 – 7 5 – 18
Catfish Synodontis contractus Bugeye squeaker 2.4 – 3.0 inch 71.6 – 78.8°F 6.2 – 7.6 3 – 15
Catfish Synodontis nigriventris Upside-down catfish 3.9 inch 71.6 – 78.8°F 6 – 8 1 – 20
Characins Alestopetersius caudalis Yellow Congo Tetra, Yellow-Tailed Congo Tetra male: 2.8 inch, female: 2.0 – 2.4 inch 71.6 – 78.8°F 7 – 7.5 12 – 16
Characins Aphyocharax anisitsi Bloodfin tetra 1.6 – 2.0 inch 71.6 – 78.8°F 5.9 – 7.2 8 – 12
Characins Aphyocharax nattereri Dawn Tetra 1.2 – 1.6 inch quite peaceful, may nip long-finned tankmates 71.6 – 80.6°F 5.5 – 7.5 1 – 15
Characins Aphyocharax rathbuni Redflank Bloodfin 1.4 – 1.8 inch quite peaceful, may nip long-finned tankmates 68.0 – 78.8°F 6.5 – 7.5 2 – 20
Characins Astyanax jordani Blind Cave Fish, Blind Cave Tetra 3.5 – 3.9 inch 68.0 – 77.0°F 6 – 7.8 20 – 30
Characins Astyanax mexicanus Mexican tetra 2.4 – 3.1 inch 68.0 – 75.2°F 6 – 8 8 – 12
Characins Boehlkea fredcochui Blue tetra, Cochu’s Blue Tetra 2.0 inch 71.6 – 78.8°F 6 – 7 5 – 12
Characins Carnegiella strigata Marbled hatchetfish 1.4 – 2.0 inch 75.2 – 84.2°F 5 – 7.5 5 – 18
Characins Chilodus punctatus Spotted headstander 2.8 – 3.1 inch 75.2 – 82.4°F 6 – 7 1 – 10
Characins Copella arnoldi Splash tetra, Jumping characin 2.4 inch 75.2 – 78.8°F 6.5 – 7 2.6 – 8.4
Characins Corynopoma riisei Swordtail characin 2.4 – 2.8 inch 71.6 – 77.0°F 6 – 8 3 – 12
Characins Crenuchus spilurus Sailfin characin 2.4 inch 75.2 – 82.4°F 5 – 6.5 1 – 5
Characins Gasteropelecus sternicla Common hatchetfish 2.6 inch 71.6 – 80.6°F 5.8 – 7.5 4 – 15
Characins Hasemania nana Silver-tipped tetra 2.0 inch 71.6 – 82.4°F 6 – 8 5 – 20
Characins Hemigrammus erythrozonus Glowlight Tetra 1.6 – 1.8 inch 71.6 – 82.4°F 6 – 7.5 6 – 15
Characins Hemigrammus hyanuary January Tetra 1.6 inch 73.4 – 80.6°F 6 – 7.5 0 – 15
Characins Hemigrammus ocellifer Head-and-tail light tetra 1.6 – 1.8 inch 75.2 – 82.4°F 5.5 – 7.5 5 – 19
Characins Hemigrammus pulcher Pretty Tetra 1.6 – 1.8 inch 73.4 – 80.6°F 5.5 – 7 1 – 12
Characins Hemigrammus ulreyi Broken-line Tetra 2.0 inch 73.4 – 80.6°F 5.8 – 7.2 5 – 12
Characins Hyphessobrycon bifasciatus Yellow tetra 1.6 – 2.0 inch 68.0 – 77.0°F 5.5 – 7.5 5 – 20
Characins Hyphessobrycon columbianus Colombian Tetra 2.0 – 2.6 inch 68.0 – 82.4°F 5 – 7.5 1 – 12
Characins Hyphessobrycon eques Serpae Tetra, Jewel Tetra, Callistus Tetra, Blood Characin 1.6 – 1.8 inch 75.2 – 82.4°F 5.5 – 7.5 3 – 12
Characins Hyphessobrycon flammeus Flame tetra, Red tetra 1.6 inch 73.4 – 78.8°F 6.5 – 7.2 5.6 – 11.2
Characins Hyphessobrycon herbertaxelrodi Black neon tetra 1.6 inch 71.6 – 82.4°F 6.8 – 7.2 5.6 – 6.7
Characins Hyphessobrycon heterorhabdus Flag Tetra 1.2 – 1.4 inch 68.0 – 82.4°F 5.5 – 7.5 5 – 15
Characins Hyphessobrycon megalopterus Black phantom tetra 1.8 inch 75.2 – 78.8°F 6 – 7.5 3.3 – 4.2
Characins Hyphessobrycon pulchripinnis Lemon tetra 1.6 inch 71.6 – 80.6°F 6.5 – 7 4.5 – 7.3
Characins Hyphessobrycon scholzei Blackline Tetra 1.6 – 2.0 inch 71.6 – 82.4°F 6.8 – 8.0 5 – 25
Characins Hyphessobrycon sweglesi Red phantom tetra 1.6 inch 68.0 – 75.2°F 6.5 – 7.2 4.5 – 8.5
Characins Hyphessobrycon takasei Coffee Bean Tetra 1.2 – 1.6 inch 71.6 – 80.6°F 5.5 – 7.4 2 – 14 NK°
Characins Inpaichthys kerri Purple Emperor Tetra Male: 1.6 inch, female: 1.2 inch 75.2 – 80.6°F 5.5 – 7.0 1 – 12
Characins Knodus borki 2.0 inch 71.6 – 78.8°F 5.5 – 7 5 – 12
Characins Nannostomus eques Brown pencilfish 2.4 inch 77.0 – 82.4°F 5.5 – 7 2.8 – 8.4
Characins Nannostomus trifasciatus Three-lined Pencilfish 1.6 – 2.4 inch a little aggressive 71.6 – 82.4°F 4 – 7.5 1 – 12
Characins Paracheirodon axelrodi Cardinal tetra 2.0 inch 73.4 – 80.6°F 6 – 7.2 2 – 8.5
Characins Paracheirodon innesi Neon tetra 1.6 inch 68.0 – 75.2°F 6.5 – 7.2 10 – 15
Characins Pristella maxillaris X-ray tetra 1.6 – 2.0 inch 71.6 – 82.4°F 6.0 – 8.0 2 – 20
Characins Thayeria boehlkei Blackline penguinfish 3.1 inch 71.6 – 78.8°F 6.5 – 7.2 4.5 – 8.5
Cichlids Anomalochromis thomasi African butterfly cichlid 2.4 – 2.8 inch territorial 75.2 – 78.8°F 6 – 7.5 8 – 10
Cichlids Apistogramma agassizii Agassiz’s dwarf cichlid male: 2.8 – 3.1 inch; female: 2.0 inch territorial 77.0 – 78.8°F 5 – 7 0 – 12
Cichlids Apistogramma baenschi Inca cichlid male: 2.2 inch, female 1.6 inch territorial and aggressive during spawning 75.2 – 82.4°F 4 – 6.5 1 – 5
Cichlids Apistogramma bitaeniata Banded Dwarf Cichlid, Two-striped Apisto male: 3.5 inch; female: 2.6 inch territorial and tolerant with its own species 75.2 – 80.6°F 5.5 – 7 2 – 6
Cichlids Apistogramma borelli Yellow dwarf cichlid, Borelli’s dwarf cichlid male: 2.8 inch, female: 2.0 inch territorial 71.6 – 78.8°F 5 – 7 1 – 10
Cichlids Apistogramma cacatuoides Cockatoo dwarf cichlid, Crested dwarf cichlid male: 3.1 inch, female: 2.0 inch territorial and polygamous 75.2 – 78.8°F 6 – 8 1 – 15
Cichlids Apistogramma hongsloi Red-lined dwarf cichlid, Red Streak Cichlid, Rotstrich Cichlid, Blackseam Cichlid male: 3.0 inch, female: 1.8 inch peaceful, territorial 75.2 – 80.6°F 5 – 6.5 0 – 15
Cichlids Apistogramma macmasteri Macmaster’s Apisto male: 2.8 inch; female: 1.6 – 2.0 inch territorial and aggressive during spawning 75.2 – 82.4°F 5.5 – 6.8 1 – 5
Cichlids Apistogramma nijsseni Panda dwarf cichlid, Nijsseni’s dwarf cichlid male: 3.1 inch, female: 2.0 – 2.4 inch peaceful, territorial 75.2 – 80.6°F 4.5 – 7.5 0 – 8
Cichlids Apistogramma panduro Azure dwarf cichlid, Blue sky dwarf cichlid male: 3.0 – 3.1 inch, female 2.0 – 2.2 inch territorial and aggressive during spawning 71.6 – 84.2°F 4 – 6.5 1 – 5
Cichlids Apistogramma trifasciata Three-stripe dwarf cichlid male: 2.4 inch, female: 1.6 inch territorial and polygamous 77.0 – 82.4°F 6 – 7 0 – 15
Cichlids Badis badis Badis, Blue Perch, Dwarf Chameleon Fish 3.1 inch may become territorial in a species tank 71.6 – 75.2°F 6 – 8 3 – 16
Cichlids Dicrossus filamentosus Chessboard Cichlid male: 3.5 inch, female: 2.4 inch territorial, aggressive during the spawning 71.6 – 78.8°F 5 – 6.75 2 – 15
Cichlids Dicrossus maculatus Spadetailed Checkerboard Cichlid male: 3.5 inch, female: 3.1 inch territorial during spawning 78.8 – 86.0°F 3.4 – 5.4 0 – 5
Cichlids Hemichromis lifalili Blood-Red Jewel Cichlid 4.3 inch territorial and aggressive, especially during spawning 73.4 – 78.8°F 6 – 7.8 4 – 15
Cichlids Laetacara dorsigera Redbreast acara 2.4 – 2.8 inch peaceful, can be kept with small tetras, a little territorial during spawning 68.0 – 82.4°F 5 – 7.5 2 – 15
Cichlids Mikrogeophagus ramirezi Ram cichlid, Butterfly cichlid 2.4 – 3.1 inch peaceful, can be kept with other non-aggressive fish 78.8 – 84.2°F 6 – 7.5 6 – 14
Cichlids Nanochromis transvestitus 1.2 – 1.6 inch males can be quite aggressive and territorial with conspecifics 75.2 – 80.6°F 4 – 7 0 – 12
Cichlids Neolamprologus brevis Brevis Shell Dweller male: 2.4 inch, female: 1.6 inch territorial 73.4 – 80.6°F 7.5 – 9.0 8 – 25
Cichlids Pelvicachromis pulcher Kribensis, Purple cichlid, Common krib, Rainbow krib 3.1 – 3.9 inch peaceful, territorial but not aggressive during spawning 77.0 – 78.8°F 4.8 – 7.5 0 – 12
Cyprinids Barbodes semifasciolatus var. ‘Schuberti’ Gold barb 2.8 inch 73.4 – 77.0°F 6 – 8 5 – 8.5
Cyprinids Brachydanio albolineata Pearl danio 2.4 inch 68.0 – 77.0°F 6.7 – 7.2 5.6 – 14
Cyprinids Brachydanio kyathit Orange-Finned Danio 1.6 – 2.0 inch 68.0 – 78.8°F 6.5 – 7.5 2 – 10
Cyprinids Brachydanio rosea Rosy Danio 2.0 – 2.2 inch 64.4 – 77.0°F 6 – 7.5 2 – 15
Cyprinids Desmopuntius pentazona Five-banded barb 2.0 inch 71.6 – 78.8°F 6 – 6.5 5 – 10
Cyprinids Desmopuntius rhomboocellatus Snakeskin Barb, Rhomb Barb, Rhombo Barb 2.0 – 3.1 inch 73.4 – 82.4°F 5 – 7 1 – 10
Cyprinids Garra flavatra Panda Garra 2.8 – 3.5 inch 71.6 – 80.6°F 6.5 – 7.5 2 – 12
Cyprinids Oliotius oligolepis Checkered barb 2.0 inch 69.8 – 82.4°F 6.6 – 6.8 8 – 15
Cyprinids Pethia cummingii Two spot barb 2.0 inch 71.6 – 80.6°F 5.5 – 7 1 – 12
Cyprinids Pethia nigrofasciata Black-ruby barb 2.4 inch 71.6 – 78.8°F 6 – 7 1 – 12
Cyprinids Pethia padamya Odessa Barb, Scarlet Barb 2.8 inch 68.0 – 78.8°F 6 – 8 5 – 20
Cyprinids Pethia ticto Two-spot barb, Ticto barb 3.1 inch 66.2 – 78.8°F 6 – 7 3 – 15
Cyprinids Rasboroides vaterifloris Orange-finned barb, Singhalese Fire Rasbora 1.6 inch 77.0 – 82.4°F 6.5 – 6.8 4.5 – 8.5
Cyprinids Trigonopoma pauciperforatum Red-line rasbora 2.0 inch 71.6 – 80.6°F 6 – 6.5 2.8 – 5.6
Cyprinids Trigonostigma heteromorpha Harlequin rasbora 1.6 inch 75.2 – 82.4°F 6 – 6.5 4.5 – 8.5
Invertebrate Marisa cornuarietis Giant ramshorn snail 1.4 – 2.0 inch 64.4 – 82.4°F 7.2 – 8.0 10 – 25
Invertebrate Atya gabonensis African Giant Filter Shrimp, African Fan Shrimp, Vampire Shrimp 4.7 – 5.9 inch quite peaceful, and will not harm even the smallest fry or other shrimps 73.4 – 84.2°F 6.5 – 7.8 2 – 10
Invertebrate Cherax quadricarinatus Redclaw Crayfish, Blue Lobster, Australian red claw crayfish 7.1 – 7.9 inch species tank, females are territorial when with eggs 59.0 – 86.0°F 7.2 – 7.8 10 – 30
Invertebrate Procambarus clarkii Red Swamp Crayfish 3.9 – 4.7 inch species tank, very territorial and aggressive to other crayfish 68.0 – 80.6°F 7.5 – 8 8 – 18
Killifish Aphanius dispar dispar Arabian Killifish 2.8 inch peaceful 59.0 – 86.0°F 7.5 – 9 15 – 35
Killifish Epiplatys dageti Red-chinned Panchax, Black-lipped Panchax 2.0 – 2.8 inch become aggressive with age, females fight each other during spawning 69.8 – 75.2°F 6 – 7 2 – 10
Killifish Fundulopanchax sjostedti Golden Pheasant, Red Aphyosemion 5.5 inch species tank, predatory towards small fish. 71.6 – 78.8°F 6 – 7 2 – 12
Killifish Jordanella floridae Florida Flagfish, American Flagfish 2.0 – 2.2 inch species tank, males can be territorial and nippy 64.4 – 86.0°F 6.5 – 8.5 2 – 20
Killifish Pachypanchax playfairii Playfair’s Panchax, Jeweled Panchax, Sawback Killifish, Seychelles Killifish 3.9 inch aggressive, territorial predator 73.4 – 77.0°F 6.5 – 7 5 – 15
Killifish Poropanchax normani Norman’s lampeye 1.6 inch peaceful 71.6 – 78.8°F 6.5 – 7.2 5 – 12
Labyrinth Betta macrostoma Brunei Beauty 3.9 – 4.3 inch species tank, males (even females) will fight with each other 68.0 – 78.8°F 3.5 – 6 0 – 10
Labyrinth Betta splendens Betta, Siamese fighting fish 2.4 – 2.8 inch highly pugnacious behavior towards one another 75.2 – 82.4°F 6.8 – 7.5 5.6 – 11.2
Labyrinth Ctenopoma weeksii Mottled ctenopoma 3.9 inch species tank, become predatory toward smaller fish 75.2 – 82.4°F 6.2 – 7.2 4 – 15
Labyrinth Macropodus ocellatus Roundtail Paradise Fish 3.1 inch may harass any similarly-shaped or long-finned tankmates 60.8 – 75.2°F 6 – 7.5 5.6 – 11.2
Labyrinth Macropodus opercularis Paradise fish, Paradise gourami 3.1 – 4.3 inch aggressive males 50.0 – 86.0°F 6 – 7.5 5.6 – 11.2
Labyrinth Macropodus spechti concolor Black paradise fish 4.7 inch aggressive 64.4 – 77.0°F 6.5 – 7 5.6 – 8.4
Labyrinth Microctenopoma fasciolatum Banded ctenopoma 3.1 inch males can be territorial with each other 75.2 – 82.4°F 6.5 – 7.5 4 – 20
Labyrinth Pseudosphromenus cupanus Spiketail Paradisefish 2.4 – 2.6 inch 68.0 – 82.4°F 6.0 – 7.5 2 – 25
Labyrinth Pseudosphromenus dayi Brown Spike-Tailed Paradise Fish, Spike-Tailed Gourami 2.6 – 3.0 inch 75.2 – 82.4°F 6 – 7.5 5 – 15
Labyrinth Sphaerichthys vaillanti Samurai Gourami, Vaillant’s Chocolate Gourami 1.8 – 2.2 inch 69.8 – 77.0°F 3.5 – 6.5 0 – 5
Labyrinth Trichogaster fasciata Banded Gourami, Indian Giant Gourami, Rainbow Gourami, Striped Gourami male: 3.9 inch, female: 2.4 – 3.1 inch 69.8 – 82.4°F 6 – 7.5 4 – 15
Labyrinth Trichogaster labiosa Thick-lipped Gourami, Thicklip Gourami 2.4 – 3.1 inch 71.6 – 80.6°F 6 – 7.5 5 – 15
Labyrinth Trichogaster lalius Dwarf gourami 1.6 inch 60.8 – 82.4°F 6.5 – 7.2 5.5 – 6.72
Labyrinth Trichopsis vittata Croaking gourami 2.4 – 2.8 inch peaceful, males are occasionally aggressive during spawning 78.8 – 82.4°F 5.5 – 8 2.8 – 5.6
Livebearers Alfaro cultratus Knife Livebearer, Knife-edged Livebearer 3.0 inch can be aggressive with conspecifics 75.2 – 82.4°F 6 – 8 5 – 20
Livebearers Allotoca dugesii Opal allotoca, Bumblebee Goodeid 2.4 – 2.6 inch males are quite aggressive with each other 64.4 – 75.2°F 7 – 8 7 – 20
Livebearers Characodon audax Bold characodon 2.0 inch quite aggressive males, may harass females constantly 68.0 – 75.2°F 7 – 8 6 – 20
Livebearers Limia melanogaster Black-bellied Limia male: 2.0 inch, female: 2.4 inch 71.6 – 82.4°F 7.5 – 8.5 15 – 30
Livebearers Limia nigrofasciata Blackbarred limia male: 1.6 – 2.2 inch, female: 1.6 – 2.4 inch 75.2 – 82.4°F 7 – 8 10 – 25
Livebearers Limia vittata Cuban limia male: 2.4 – 2.8 inch, female: 3.9 inch 75.2 – 82.4°F 7 – 8.2 25 – 30
Livebearers Phallichthys amates Merry Widow male: 2.0 inch, female: 2.4 inch 71.6 – 82.4°F 6.5 – 7.5 10 – 25
Livebearers Poecilia sphenops Black molly male: 2.4 – 2.8 inch, female: 3.1 – 3.5 inch 77.0 – 82.4°F 7.5 – 8.2 11 – 30
Livebearers Priapella intermedia male: 2.0 inch, female: 2.8 inch 77.0 – 82.4°F 7 – 8 9 – 19
Livebearers Skiffia francesae Golden skiffia 2.0 inch 57.2 – 71.6°F 7 – 9 2 – 35
Livebearers Xiphophorus variatus Variegated platy, Variatus platy male: 1.6 – 2.2 inch, female: 2.6 inch 75.2 – 82.4°F 7 – 8 10 – 20
Livebearers Zoogoneticus tequila Tequila splitfin male: 2.4 inch, female: 3.1 inch quite aggressive with each other 68.0 – 75.2°F 6.5 – 7.5 10 – 25
Loaches Acanthocobitis botia Zipper Loach, Mottled Loach, Eye-Spot Loach, Sand Loach, Striped Loach 3.1 – 3.9 inch 69.8 – 78.8°F 6.5 – 7.2 15 – 25
Loaches Ambastaia nigrolineata Black-Lined Loach 3.1 – 3.9 inch 68.0 – 77.0°F 6.5 – 7.5 5 – 15
Loaches Ambastaia sidthimunki Dwarf Loach, Dwarf Chain Loach 2.4 inch 75.2 – 82.4°F 6 – 7.5 1 – 15
Loaches Beaufortia kweichowensis Butterfly Loach 2.6 – 3.0 inch peaceful and shy loach, males are territorial 60.8 – 75.2°F 6.5 – 8 1 – 12
Loaches Gastromyzon ctenocephalus Borneo Sucker 1.4 – 1.6 inch peaceful and shy loach, territorial 68.0 – 75.2°F 6 – 7.5 1 – 12
Loaches Pangio anguillaris Eel Loach 3.9 – 4.7 inch 73.4 – 84.2°F 6 – 7.5 0 – 8
Loaches Pangio kuhlii Coolie Loach, Kuhli Loach, Prickly Eye 4.3 inch 77.0 – 82.4°F 6.2 – 6.8 4 – 15
Loaches Pangio oblonga Java Loach 3.1 inch 73.4 – 84.2°F 3.5 – 7 0 – 8
Loaches Pangio pangia Cinnamon Loach 2.4 inch 75.2 – 78.8°F 6 – 7 1 – 12
Loaches Sewellia lineolata Gold Ring Butterfly Sucker, Reticulated Hillstream Loach, Tiger Hillstream Loach 2.2 – 2.6 inch 68.0 – 75.2°F 6 – 7.5 1 – 10
Other Carinotetraodon irrubesco Red-tailed Redeye Puffer 1.6 – 1.8 inch males can be territorial 68.0 – 82.4°F 6 – 7.5 2 – 12
Other Monocirrhus polyacanthus Leaf Fish, Amazon Leaffish, South American Leaf Fish 3.9 inch males can be very aggressive and territorial 71.6 – 77.0°F 5 – 6.8 1 – 10
Other Pantodon buchholzi Butterflyfish, African Butterfly Fish 3.9 inch intolerant with surface fish 75.2 – 86.0°F 6 – 7 1 – 15
Other Stiphodon ornatus Rainbow Stiphodon Goby 2.0 – 2.6 inch peaceful but males are loosely territorial, especially during breeding 68.0 – 82.4°F 6.5 – 7.5 2 – 12
Other Tateurndina ocellicauda Peacock gudgeon 2.0 inch 75.2 – 77.0°F 6.5 – 7.5 5.6 – 8.4
Rainbowfish Iriatherina werneri Threadfin Rainbowfish, Featherfin Rainbowfish male 2.0 inch, female 1.4 inch 75.2 – 86.0°F 5.5 – 7.5 5 – 12
Rainbowfish Marosatherina ladigesi Celebes Rainbowfish male: 2.4 – 3.1 inch, female: 2.0 – 2.8 inch 71.6 – 82.4°F 6 – 7 10 – 25
Rainbowfish Melanotaenia maccullochi Dwarf rainbowfish, Black-lined Rainbowfish 2.8 inch 71.6 – 82.4°F 5.5 – 7.5 8 – 18
Rainbowfish Popondichthys furcatus Forktail rainbowfish, Forktail Blue-eye 2.0 – 2.4 inch 75.2 – 82.4°F 7 – 8 5 – 12

And over a hundred species for 5-gallon tank and 10-gallon tank.

Setup ideas for a 20-gallon tank

There are so many options when it comes to aquascaping and this depends on the style you’re aiming for. But what is aquascaping? This is the art of laying out aquariums with hardscapes such as rocks, stones, wood, and plants. There are a few common styles and we’ll cover some options for you.

Planted aquarium

20-gallon-planted-tank

If you have a 20 gallon planted aquarium then a natural aquascape makes sense. This uses the plants within your tank to create a natural scape that resembles a natural landscape. You can use rocks and wood that you can plant on to build up the scape to look more realistic. Moss is your best friend when it comes to this style of scaping.

If you’d like a planted tank then how many can you have? Well, there’s no hard and fast rule for this, you can keep as many plants as the tank can fit but ensure all the plants can get enough light they need, and the rest space is abundant for fish to swim around. Adding too many plants will require more maintenance, too.

Fish-only aquarium without plants

20-gallon-fish-tank

If you want to make your decorations as the central piece of the aquascape, you may set up your tank in this kind. It is easy to maintain and clean with a tank without live plants. You don’t have to trim your plants and remove dead leaves weekly. Cleaning the gravel is much easier without any obstructive plants.

The best aquascaping for a fish-only tank is to use hardscaping materials only; gravel, rock, wood, plastic plants, and decorations work best in this instance. You can balance the colors and textures with any ornamental decorations you may have within the tank. This will allow you to create a landscape that is natural-looking without greenery.

Some live plants such as Marimo Moss Balls, Anubias, and Echinodorus can be added to supplement a little real green to the tank. These plants are low-demanding, slow-growing, and very easy to maintain.

Shrimp tank

shrimp-tank-setup

Shrimp do enjoy hiding places so many aquascaping options would work here. The best options for aquascaping a shrimp tank will include caves, wood, and plants which are everything most shrimp love. Utilize the materials to create natural hiding holes for them which look like they are part of the landscape rather than a cave sat in the middle of the floor.

Find the detailed page for shrimp here: https://portlandaquarium.net/freshwater-shrimp/

Coldwater tank (unheated tank)

zebra-danio-aquarium

Zebra Danio tank

To aquascape a cold-water tank it is best done without using plants, rocks and stones work best in these tanks. You can build up natural towers, bridges, and caves to create stunning scenery that looks like it may belong in the stone ages. You are only limited by your imagination, even when restricted with your materials.

Make sure you keep all coldwater fish such as Zebra Danios (64° – 79° F) in the tank. Some other species for a 20-gallon coldwater tank include White Cloud Mountain Minnow (64° – 72° F), Clown Killifish (68° – 79° F), Hillstream Loach (65° – 77° F), Rainbow Shiner (50° – 72° F), Endler Guppies (66° – 84° F).

Fancy Guppies are tropical fish and don’t do well in coldwater that makes them easy to get diseases. If you have Guppies in a coldwater tank, ensure the temperature doesn’t drop below 68 °F (20 °C).

Saltwater fish-only with liverock (FOWLR)

live-rock

You can aquascape a marine tank with live rock, you can create structures and natural-forming hidden caves for your fish. You need to ensure however that everything is not stacked or put together too tightly, to make for easy clean-up of fish waste. Live rock is relatively easy to stack up, to gain height within the scape.

Reef aquarium

20-gallon-reef-tank

Your imagination is your best friend when scaping a reef tank, imagine the reefs that are natural out at sea and aim to create a miniature version. You can mix colors and shapes to recreate a natural-looking formation. Do not worry about perfection when doing a reef scape as it is not perfect out in the deep blue sea. Random reefs placed strategically work best in this setup.

Species tank

dwarf-puffer-tank

Dwarf Puffer tank

This kind of aquariums is also suitable for some specific species, which are aggressive to other fish or with specific care requirements, such as Puffers, Dwarf cichlids, Dwarf Gouramis, Bettas, etc. You can keep one or two species with the closed water requirements in the same tank.

To aquascape a species tank, you need to fit the scaping in with the fish you keep. If you have a Betta tank, they enjoy resting places, that can be easily added and combined with your overall scaping look. You can keep multiple male Bettas in a 20-gallon tank with the help of dividers.

Aquaponics fish tank

ECO-Cycle Aquaponics Indoor Garden SystemECO-Cycle Aquaponics Indoor Garden System

It is a self-sufficient tank and already has a natural look, due to the plants that grow above it. It will look stunning with a green planted floor and a few rocks placed around. You will need a 20-gallon aquaponics kit to build your tank this way.

Lucas has been keeping successful fish, planted, and reef tanks for many years. He loves to collect aquatic organisms and have as many aquariums as he can afford.

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