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How Big is a 5 Gallon Aquarium L x W x H

The usefulness of 5 gallon aquarium dimensions is the main reason why they are an excellent choice for beginners and in areas where there is limited space.

They are practical, aesthetic, and an affordable option offering the ideal balance between ease of care and creative aquascaping possibilities.

Dimensions of a Rectangular 5 Gallon Tank

Here's everything you need to know about 5 gallon aquariums (19 L).

Aquarium Dimensions in Centimetres and Inches

5 gallon tank: 16" L x 8" W x 10" H (40.6 x 20.3 x 25.4 cm)

Weight in Pounds and Kilograms

5 gallon tank weight (empty): 7 pounds (3.2 kg)
5 gallon tank weight (filled with water): 62 pounds (28 kg)

Important: Aquarium dimensions vary slightly by brand. So, always confirm the exact size before buying a stand or lid. Another section contains information about 20-gallon tank dimensions in cm and inches.

There are two different types of fish tanks - glass and acrylic. Glass aquariums are durable and scratch-resistant - but extremely heavy when filled with water. Whereas, acrylic containers are lightweight and cheaper - but prone to scratches.

Even so, always place a large aquarium away from direct sunlight, drafts, and heat sources. This is the best way to avoid algae growth and reduce temperature fluctuations.

Benefits of a 5-Gallon Aquarium

Aquariums that hold five (5) US gallons of water are relatively easy to maintain and more affordable - when compared to much larger tanks.
Planted nano tanks are about half the size of 10-gallon rectangular aquariums, so they are ideal for small space setups (e.g. a desktop).
You have some space to keep small freshwater fish species (e.g. betta fish, tetras) or aquatic creatures (e.g. shrimps, snails).

Best Types of Fish for 5 Gallon Tank

So, now you need to know how many fish you can have in a five gallon aquarium that measures 16 inches long, 8 inches wide, and 10 inches high.

Having a compact small-scale container means you will only be able to keep certain kinds of fish families. Some of the popular species that are suitable for 5 gallon tanks include:

Betta fish (Betta splendens): Often called the Siamese fighting fish, they are very colourful with flowing fins and easy fish to care for even with gentle filtration. But, it's best to only keep a single betta with other peaceful species (e.g. corydoras).
Chili rasbora (Boraras brigittae): They are small schooling fish but they will need stable filtration.
Ember tetra (Hyphessobrycon amandae): They have bright orange body colouration and tend to be a peaceful freshwater schooling fish.
Least killifish (Heterandria formosa): Sometimes known as the dwarf topminnow, they are hardy and one of the smallest livebearers. They are also quite easy to breed for beginners who keep them as pets.

It's best to avoid putting goldfish (they will grow too big), guppies (they breed too fast), and neon tetras (because they like to school in large groups) in a 5-gallon fish tank.

Non Fish Aquatic Pets

What if you want to keep something other than fish in a small tank that only holds 5 gallons (19 L)? If so, consider keeping some of these non-fish creatures instead:

Amano shrimp (Caridina multidentata): Having a wide tolerance for water temperature makes them ideal to keep as freshwater cleaner shrimps.
Cherry Shrimp (Neocaridina davidi): This red coloured critter is fun to observe and they generally don't grow bigger than three (3) centimetres.
Mystery snail (Pomacea bridgesii): Despite being able to hibernate for extended periods (sometimes several months) they can survive a range of adverse conditions. Make sure you have a secure lid on the aquarium because they will try to escape. Another section has a list of goofy fish names but this snail is so-called because females can give birth to young snails that are fully developed and "mysteriously" appear out of nowhere (e.g. no sign of eggs).
Nerite snails: Even though they don't reproduce in freshwater they have vibrant colouring and they are a popular species of aquarium algae-eaters.

Pro Tip: Remember to apply the stocking rule as close as possible - especially in a small 5 gallon setup - "one (1) inch of fish per gallon of water". Besides that, always consider the maximum size of adult fish when they mature and how their bio-load may affect the community.

5-Gallon Tank Aquascaping and Plant Options

Having a small setup means you have less options for aquarium hardscapes and live plants. However, you can still use rocks, coral, driftwood, and caves for aquatic animals to explore and hide inside.

With limited space available, it's best to compact decorations and low-maintenance plants so they don't overcrowd the fish. Some of the best decorations for a 5-gallon aquarium can include:

Small caves and places for fish to hide, such as:

Ceramic or resin caves
Natural rock caves (lava rock or dragon stone)
Huts made with coconut shells

Driftwood

Desert cactus skeleton is good for shrimps (e.g. cholla wood)
Mopani wood (soak it beforehand to reduce tannins)
Spider wood (create some unique shapes)

Pebbles or Smooth River Rocks

Great for creating a small cave or for stacking in piles.
Make sure they are aquarium-safe and avoid using stones with sharp edges.

Small Decorations and Ornaments

You can create a themed tank (e.g. using sunken ruins) or other miniature decorations that need very little space to be effective.

Best Live Plants for 5-Gallon Tanks

Anubias Nana
Java Fern
Java Moss
Marimo Moss Ball
Cryptocoryne Parva
Floating plants (for example watermoss or water lettuce (Pistia statiotes))

Substrate for Small Aquariums

Fine gravel or clean sand
Nutrient-rich aquarium soil

Maintenance Tips for Small Fish Tanks

Water Changes: Replace about twenty to thirty percent of the water on a weekly basis.
Filter Cleaning: Rinse the filter media in tank water every two to four weeks.
Gravel Vacuuming: Helps to remove uneaten fish food matter and debris.
Test Water Quality: Check regularly for high levels of ammonia, nitrite, and nitrate.

Pro Tip: An aquarium that holds 5 gallons (around 19 litres) offers some balance between manageable size and ease of maintenance. So, you would be able to enjoy a diverse aquarium setup while managing your time and budget effectively.