A 5 gallon fish tank is one of the most popular aquarium sizes for beginners, hobbyists with limited space, and those who want a simple and beautiful aquatic display. Its compact size makes it perfect for bedrooms, offices, small apartments, and desks. However, the biggest mistake new aquarists make is assuming that a 5-gallon tank is “easier.” In reality, a small tank requires proper planning, careful fish selection, and consistent maintenance.

This complete guide covers everything you need to know about a 5 gallon fish tank, including fish types, stocking ideas, filtration, heating, aquascaping, water parameters, and common mistakes to avoid. Whether you’re setting up your first tank or upgrading your small aquarium, this article provides a comprehensive, SEO-friendly, beginner-friendly, and expert-level overview.

What Is a 5 Gallon Fish Tank?

A 5 gallon fish tank is a compact aquarium that holds approximately 19 liters of water. It is considered a nano aquarium and is ideal for small fish species, shrimp, snails, and aquatic plants. Because it is small, it requires:

• Careful stocking
• Proper filtration
• Stable water temperature
• Frequent water changes

Despite its small size, a 5 gallon tank can be turned into a beautiful aquascape with vibrant plants and colorful micro-fish.

Why Choose a 5 Gallon Fish Tank?

1. Space-Saving

It fits on tables, desks, side shelves, and countertops without occupying much room.

2. Beginner-Friendly

When stocked correctly, it’s easier to manage than larger tanks.

3. Affordable

Equipment for a 5 gallon tank—heater, filter, substrate, plants—is budget-friendly.

4. Great for Betta Fish & Shrimp

Many iconic small aquarium species thrive in a 5 gallon size.

5. Ideal for Aquascaping

A 5 gallon tank is perfect for nano planted tank layouts like:

• Iwagumi
• Jungle style
• Nature style

Best Fish for a 5 Gallon Fish Tank

Choosing the right fish is extremely important because you cannot keep medium or schooling fish in such a small size. Here are the best fish that can live comfortably and healthily in a 5 gallon aquarium.

1. Betta Fish (Siamese Fighting Fish)

The most recommended fish for a 5 gallon tank.

Why They Are Great:

• Thrive in smaller aquariums
• Come in beautiful colors and tail types
• Low bioload
• Enjoy slow-moving water

Key Requirements:

• One male betta per tank
• Heavily planted tank
• Gentle filter
• Heater (24–27°C)

2. Endler’s Livebearers (Males Only)

Small, colorful, active fish ideal for nano tanks.

Stocking:

• 3–4 males only (females will overbreed)

Benefits:

• Peaceful
• Hardy
• Great movement and color

3. Ember Tetras (Tiny School)

One of the only tetra species that can fit in a 5 gallon.

Stocking:

• 6 Ember Tetras (max)

Benefits:

• Peaceful schooling fish
• Bright orange color
• Low waste

4. Chili Rasboras / Phoenix Rasboras

Extremely small, perfect for nano tanks.

Stocking:

• 6–8 rasboras

Benefits:

• Stunning micro-fish
• Love live plants
• Great community options

5. Scarlet Badis (Dario dario)

Stocking:

• 1 male OR 1 male + 1–2 females

Benefits:

• Beautiful coloration
• Slow-moving, calm fish

Note:

They require live foods (micro worms, baby brine shrimp).

Non-Fish Options for a 5 Gallon Tank

Not every 5-gallon aquarium needs fish. These alternatives are low-maintenance, fascinating, and produce less waste.

1. Shrimp Tank (Neocaridina or Caridina)

Perfect for beginners, especially cherry shrimp.

Stocking:

• 10–20 shrimp

Benefits:

• Easy to breed
• Clean the tank
• Colorful nano pets

2. Snails

Great cleanup crew.

Best Types:

• Nerite Snail
• Mystery Snail
• Ramshorn Snail

Stocking:

• 1–2 snails

3. Nano Aquascape Only

A plant-only tank is a beautiful art piece and requires no fish.

Fish to Avoid in a 5 Gallon Tank

These species need bigger tanks and should NEVER be kept in a 5 gallon aquarium:

• Goldfish
• Guppies (overbreed quickly)
• Mollies
• Platies
• Swordtails
• Zebra Danios
• Angelfish
• Oscar fish
• Corydoras (except pygmy cory, but still needs 10 gallons)
• Any large schooling fish

Different Types of 5 Gallon Fish Tanks

You can choose from several tank styles depending on your aesthetic and needs.

1. Glass 5 Gallon Aquarium

Most durable and scratch-resistant.

Pros:

• Clear view
• Long-lasting

Cons:

• Heavy

2. Acrylic 5 Gallon Tank

Lightweight and attractive.

Pros:

• Clearer than glass
• Lightweight

Cons:

• Scratches easily

3. Rimless 5 Gallon Tank

Modern and stylish.

Pros:

• Sleek design
• Ideal for aquascaping

Cons:

• More expensive

4. 5 Gallon Bow Front Tank

Curved front gives a magnifying effect.

5. 5 Gallon Cube Tank

Perfect for nano communities and aquascaping.

6. 5 Gallon Starter Kits

Include filter, light, and sometimes a heater.
Great for beginners.

Stocking Ideas for a 5 Gallon Tank

Here are several complete stocking combinations.

1. Betta Paradise Tank

• 1 Betta
• Live plants
• 1 Nerite Snail (optional)

2. Nano Schooling Tank

• 6 Ember Tetras or Chili Rasboras
• Plants and hiding spots

3. Shrimp Colony Tank

• 15 Cherry Shrimp
• Nano plants
• Driftwood & moss

4. Peaceful Micro Community

• 1 Male Endler
• 5 Chili Rasboras
• 1 Nerite Snail

5. Aquascape Display (No Fish)

• Carpet plants (Monte Carlo, dwarf hair grass)
• Rocks, wood, moss

Essential Equipment for a 5 Gallon Fish Tank

Even a small aquarium needs proper equipment.

1. Filter

Must be gentle to avoid strong currents.
Best filter types:

• Sponge filter
• Internal nano filter
• Low-flow hang-on-back filter

2. Heater

Maintains stable temperature of 24–27°C.

3. Substrate

Options include:

• Sand
• Gravel
• Soil (for planted tanks)

4. LED Light

Vital for plant growth and enhancing fish colors.

5. Water Conditioner

Removes chlorine and harmful chemicals.

6. Aquarium Tools

• Net
• Siphon
• Bucket
• Algae scraper

Setting Up a 5 Gallon Fish Tank — Step-by-Step Guide

Step 1: Rinse the Tank and Substrate

Never use soap.

Step 2: Add Substrate and Hardscape

Place stones, driftwood, and plants.

Step 3: Install Filter and Heater

Ensure gentle flow.

Step 4: Add Treated Water

Use a water conditioner.

Step 5: Start the Nitrogen Cycle

This takes 2–4 weeks.
Add fish only after ammonia and nitrites reach 0.

Step 6: Add Fish Slowly

Do not overcrowd.

Step 7: Maintain Regularly

Weekly water changes are necessary.

Maintenance Schedule for a 5 Gallon Tank

Because the volume is small, parameters change quickly.

Weekly Maintenance

• 30–40% water change
• Clean glass
• Trim plants

Bi-Weekly

• Rinse filter sponge in old tank water

Monthly

• Check heater accuracy
• Deep clean decorations

Common Mistakes to Avoid

• Overfeeding
• Overcrowding
• Keeping incompatible fish
• Skipping water changes
• Using strong filters
• Adding fish before cycling

FAQs About 5 Gallon Fish Tanks

1. Is a 5 gallon tank good for beginners?

Yes, but it requires careful stocking and regular maintenance.

2. Can multiple fish live in a 5 gallon tank?

Only small species. Most tanks should have one betta or a small school of microfish.

3. Do I need a filter?

Yes. A filter keeps water clean and stable.

4. Do I need a heater?

For tropical fish, absolutely.

5. Is a 5 gallon tank too small for goldfish?

Yes. Goldfish need 20–40 gallons minimum.

6. How often should I clean a 5 gallon tank?

Weekly partial water changes are required.

7. What is the best fish for a 5 gallon tank?

A betta fish is the most recommended.

8. Can shrimp live in a 5 gallon tank?

Yes, they thrive and reproduce well in a 5 gallon setup.

9. How many fish can I put in a 5 gallon tank?

Usually 1 betta or a small school of 6 microfish.

10. Can I use a 5 gallon tank for aquascaping?

Yes! It’s perfect for nano layouts.