One of the first questions every new fishkeeper asks is:
“What size aquarium should I buy?”
It’s a great question, and the answer may surprise you.
Many beginners assume that smaller aquariums are easier to maintain because they’re cheaper, take up less space, and require less water. However, in the world of fishkeeping, bigger is often better—especially when you’re just starting out.
Choosing the right aquarium size can make the difference between a thriving, enjoyable hobby and a frustrating experience filled with water quality problems and stressed fish.
In this guide, we’ll explain why aquarium size matters, which tank sizes are best for beginners, and how to choose the perfect aquarium for your home and your future fish.
Why Aquarium Size Matters
When you’re new to fishkeeping, it’s easy to focus on appearance or available space.
However, aquarium size directly affects:
- Water stability
- Fish health
- Maintenance requirements
- Stocking options
- Long-term success
Larger aquariums generally provide a more stable environment, making them much more forgiving when beginner mistakes occur.
The Biggest Myth in Fishkeeping
One of the most common misconceptions is that small aquariums are easier to care for.
In reality:
Small Tanks Change Quickly
In a small aquarium:
- Temperature fluctuates faster
- Waste builds up more quickly
- Water chemistry changes rapidly
- Mistakes have a bigger impact
Larger Tanks Are More Stable
A larger volume of water acts as a buffer against sudden changes.
This stability makes life easier for both fish and fishkeepers.
Why Bigger Is Often Better
Imagine spilling a teaspoon of food into:
- A 20-litre aquarium
- A 200-litre aquarium
The impact on water quality will be far greater in the smaller tank.
Similarly, fish waste, evaporation, and temperature changes all have a more dramatic effect in smaller aquariums.
This is why experienced aquarists often recommend avoiding extremely small tanks for beginners.
The Ideal Beginner Aquarium Size
For most first-time fishkeepers, the sweet spot is:
60 to 120 Litres
This size range offers several advantages:
- Stable water conditions
- Good fish stocking options
- Manageable maintenance
- Affordable running costs
- Plenty of aquascaping potential
Aquariums in this size range provide enough water volume to be forgiving while remaining practical for most homes.
Why a 60-Litre Aquarium Is a Great Starting Point
A 60-litre aquarium is often considered one of the best beginner sizes.
Benefits include:
Easy to Maintain
Water quality remains relatively stable.
Affordable Equipment
Filters, heaters, and lighting are readily available.
Suitable for Many Fish Species
Including:
- Neon Tetras
- Harlequin Rasboras
- Guppies
- Platies
- Corydoras Catfish
Fits Most Homes
Large enough for success without dominating a room.
Why 90–120 Litres May Be Even Better
If space and budget allow, a slightly larger aquarium offers even greater flexibility.
Advantages include:
More Stocking Options
You can keep larger schools of fish and more varied communities.
Greater Stability
More water means more forgiveness when things go wrong.
Better Aquascaping Opportunities
Larger tanks provide more room for:
- Plants
- Driftwood
- Rocks
- Natural layouts
Many hobbyists who start with a 90-litre or 120-litre aquarium find they rarely outgrow it.
Are Nano Aquariums Suitable for Beginners?
Nano aquariums typically hold less than 40 litres.
While they are popular and attractive, they present additional challenges.
Potential Issues
- Rapid parameter changes
- Limited stocking options
- Greater maintenance sensitivity
- Faster temperature fluctuations
Nano tanks can be successful, but they often require more attention than larger aquariums.
For complete beginners, a larger tank is usually the safer option.
What About Fish Bowls?
Fish bowls remain one of the most unsuitable environments for fish.
Problems include:
- Poor filtration
- Limited swimming space
- Small water volume
- Poor oxygen exchange
Most tropical and coldwater fish will not thrive in a traditional fish bowl.
A properly filtered aquarium is always the better choice.
Freshwater vs Marine Aquariums for Beginners
If you’re choosing your first aquarium, freshwater systems are generally recommended.
Freshwater Benefits
- Lower setup costs
- Easier maintenance
- Wider range of beginner-friendly fish
- Simpler equipment requirements
Marine aquariums can be incredibly rewarding but typically involve:
- More complex water chemistry
- Additional equipment
- Higher costs
Many successful marine hobbyists begin with freshwater aquariums before progressing to reef systems.
Popular Beginner Fish Tank Sizes
54–60 Litres
Ideal for:
- Small tropical communities
- Shrimp tanks
- Planted aquariums
90 Litres
Perfect for:
- Larger schools of fish
- Community setups
- Aquascaping projects
120 Litres
Excellent for:
- Beginner aquascapers
- Diverse fish communities
- Long-term fishkeeping success
180 Litres and Above
Suitable for hobbyists with more space and larger ambitions.
Consider Where the Aquarium Will Go
Before purchasing an aquarium, consider:
Floor Strength
Larger aquariums can become surprisingly heavy when filled.
Access to Power
You’ll need access to electrical outlets for:
- Filters
- Heaters
- Lighting
Maintenance Access
Leave room around the aquarium for cleaning and maintenance.
Natural Light
Avoid placing aquariums in direct sunlight to reduce algae issues.
Think About the Fish You Want to Keep
Your livestock plans should influence tank size.
For example:
Small Community Fish
Suitable for:
- 60–120 litre aquariums
Angelfish
Generally require larger aquariums.
Goldfish
Need significantly more space than many beginners realise.
Discus
Require larger, stable aquariums with excellent water quality.
Research your chosen fish before selecting a tank.
Common Beginner Mistakes When Choosing an Aquarium
Buying the Smallest Tank Available
Smaller isn’t necessarily easier.
Choosing Based on Price Alone
Cheaper tanks may limit future stocking options.
Ignoring Adult Fish Size
Always research how large fish will grow.
Not Planning for Growth
Many hobbyists quickly become more ambitious after starting.
A slightly larger aquarium often provides more flexibility.
Essential Equipment for a Beginner Aquarium
Regardless of size, every aquarium should include:
Filter
Provides biological and mechanical filtration.
Heater
Required for most tropical fish.
Lighting
Supports plant growth and enhances viewing.
Thermometer
Allows temperature monitoring.
Water Conditioner
Makes tap water safe for fish.
Test Kit
Essential for monitoring water quality.
Investing in quality equipment from the beginning often leads to greater success.
Why Many Beginners Upgrade Quickly
There’s a common joke in fishkeeping:
“Your first aquarium won’t be your last.”
Many hobbyists start small and quickly wish they had purchased a larger aquarium.
Reasons include:
- More fish options
- Greater aquascaping potential
- Easier maintenance
- Improved stability
Starting with the largest practical aquarium often saves money in the long run.
Our Recommended Beginner Aquarium Size
If someone walks into Charterhouse Aquatics and asks:
“What’s the best aquarium size for a beginner?”
Our answer is usually:
60–120 Litres
This range provides:
- Stability
- Flexibility
- Excellent fishkeeping potential
- Manageable maintenance
It’s large enough for success while remaining accessible to newcomers.
Final Thoughts
When it comes to beginner aquariums, bigger really is often better. While small tanks may seem appealing, larger aquariums offer greater stability, easier maintenance, and a much better chance of long-term success.
For most newcomers, an aquarium between 60 and 120 litres strikes the perfect balance between practicality and performance. Combined with proper filtration, regular maintenance, and suitable livestock, it provides an ideal introduction to the rewarding world of fishkeeping.
At Charterhouse Aquatics, we stock a wide range of beginner-friendly aquariums, aquarium kits, filtration systems, heaters, lighting, and fishkeeping essentials to help you choose the perfect first aquarium.
