What Is a Nano Aquarium?

A nano aquarium is typically between 2.5 and 10 gallons. While small in size, these tanks can support beautiful ecosystems with fish, shrimp, and live plants.

When you finish reading this guide, be sure to checkout our ultimate checklist.

Nano tanks are affordable, space-efficient, and perfect for beginners — but they require smart equipment choices and proper setup.

Step 1: Choosing the Right Tank Size

5 Gallon vs 10 Gallon

If you're buying your first tank, start here:

Step 2: Essential Equipment (Critical for Success)

Filtration

A properly sized filter prevents ammonia spikes and keeps water crystal clear.

Best Nano Aquarium Filters →

Heater

Most tropical fish need stable temperatures between 72–78°F.

Best Nano Aquarium Heaters

Lighting

Live plants require proper spectrum LED lighting.

Best Nano Aquarium Lights

Substrate

Choose gravel, sand, or aquasoil depending on your livestock and plants.

Best Substrate for Nano Tanks

Beginner Setup Checklist

Step 3: Cycling Your Tank

Before adding fish, your tank must establish beneficial bacteria through the nitrogen cycle.

This takes approximately 3–4 weeks.

Detailed instructions here: How to Cycle a Fish Tank

Step 4: Stocking Your Nano Aquarium

Best Fish for 5 Gallons

Complete 5-Gallon Stocking Guide

Best Fish for 10 Gallons

Complete 10-Gallon Stocking Guide

Shrimp Options

Best Shrimp for Nano Tanks

Step 5: Maintenance Routine

Weekly

Monthly

Common Beginner Mistakes

Start Here