Fishkeeping Basics: Setting Up and Maintaining a Healthy Aquarium

Learn fishkeeping basics with our comprehensive guide. Perfect for beginners looking to start their aquarium.

Starting a fishkeeping hobby can be a rewarding and fascinating experience. Whether you’re captivated by the serene beauty of an aquarium or interested in the challenge of maintaining an aquatic environment, understanding fishkeeping basics is essential. This guide covers everything from selecting the right tank to ensuring your fish thrive.


Fishkeeping offers a unique blend of tranquility and challenge, making it a popular hobby for many. The sight of colorful fish swimming gracefully can be incredibly soothing while creating and maintaining their habitat can be engaging and educational. However, successful fishkeeping requires more than filling a tank with water and adding fish. This comprehensive guide to fishkeeping basics will walk you through each step, ensuring you have the knowledge and confidence to create a thriving aquatic environment.

Choosing the Right Aquarium

Selecting the right aquarium is the first crucial step in your fishkeeping journey. Aquariums come in various shapes and sizes, each suited to different types of fish and environments. For beginners, a medium-sized tank of around 20 gallons is often recommended. This size is manageable yet large enough to provide a stable environment for your fish.

When choosing your tank, consider the space available in your home and the type of fish you plan to keep. Some fish require more room to swim, while others may need specific conditions such as planted or brackish water. Glass tanks are famous for their clarity and durability. In contrast, acrylic tanks are lighter and less prone to cracking.

Setting Up Your Aquarium

Once you’ve selected your aquarium, setting it up correctly is essential for the health of your fish. Begin by placing your tank on a sturdy, level surface away from direct sunlight, which can cause unwanted algae growth.

Installing the Filtration System

A sound filtration system is critical for maintaining clean and healthy water. Filters come in various mechanical, chemical, and biological types, each serving a different purpose. Combining these filters is often the best choice, ensuring thorough cleaning.

Adding Substrate and Decorations

The substrate, or the material at the bottom of the tank, is more than just decorative. It provides a surface for beneficial bacteria to grow, which helps break down waste products. Depending on your fish’s needs, gravel, sand, and specialized substrates are all options.

Decorations such as rocks, plants, and ornaments provide hiding places for fish and enhance the tank’s aesthetic appeal. Live plants are particularly beneficial as they help maintain water quality by absorbing nitrates and giving oxygen.

Cycling Your Tank

Before adding fish to your aquarium, it’s crucial to cycle the tank. Cycling is establishing beneficial bacteria in the tank’s filter media, which break down harmful ammonia and nitrite produced by fish waste. This process can take several weeks, but it is vital for creating a safe environment for your fish.

Selecting Fish for Your Aquarium

Choosing the right fish is essential for a harmonious tank. Beginners should start with hardy species that can tolerate a range of conditions. Some popular beginner fish include:

  • Betta Fish: Known for their vibrant colors and flowing fins, bettas are easy to care for and do well in smaller tanks.
  • Neon Tetras: These small, schooling fish are peaceful and add a splash of color to any tank.
  • Guppies: Hardy and prolific breeders, guppies come in various colors and patterns.
  • Corydoras Catfish: These bottom-dwellers help keep the tank clean by scavenging for food.

When selecting fish, consider their compatibility. Some species are territorial and may not coexist peacefully with others. Research each species’ needs regarding water parameters, diet, and space to ensure a harmonious community tank.

Feeding Your Fish

Proper nutrition is vital to keeping your fish healthy. Most fish thrive on a varied diet that includes high-quality flake or pellet food supplemented with live, frozen, or freeze-dried foods such as brine shrimp, bloodworms, or daphnia. Overfeeding is a common mistake that can lead to poor water quality and health issues. Feed your fish small amounts once or twice a day, only as much as they can consume in a few minutes.

Maintaining Water Quality

Regular maintenance is crucial for a healthy aquarium. Test the water parameters weekly to ensure levels of ammonia, nitrite, nitrate, pH, and hardness are within acceptable ranges for your fish. Perform partial water changes of 20-30% every two weeks to remove accumulated waste and replenish essential minerals. Clean the tank glass, substrate, and decorations as needed to prevent algae buildup and keep the tank looking pristine.

Understanding Fish Behavior and Health

Observing your fish regularly helps you spot signs of stress or illness early. Healthy fish are active, have bright colors, and display normal behaviors such as swimming, feeding, and interacting with tank mates. Common signs of illness include:

  • Changes in appetite or behavior: Loss of appetite, lethargy, or erratic swimming can indicate a problem.
  • Physical symptoms: Look for signs such as white spots (ich), clamped fins, bloating, or unusual growths.
  • Breathing difficulties: Gasping at the surface or rapid gill movement may indicate poor water quality or disease.

If you notice these signs, test your water parameters and consult a fish health guide or veterinarian for treatment advice.

Creating a Balanced Aquatic Ecosystem

A successful aquarium is a balanced ecosystem where fish, plants, and microorganisms coexist harmoniously. To achieve this balance, it’s essential to:

  • Avoid overstocking: Too many fish in a tank can lead to poor water quality and stressed fish.
  • Provide adequate filtration: Ensure your filter can handle the biological load of your tank.
  • Maintain stable water conditions: Sudden changes in temperature, pH, or other parameters can stress or kill fish.
  • Support beneficial bacteria: Avoid cleaning filter media with tap water, which can kill beneficial bacteria. Use tank water instead.

Tips for a Thriving Aquarium

  1. Research thoroughly: Before adding new fish or plants, research their specific care requirements.
  2. Quarantine new arrivals: Prevent the spread of disease by quarantining new fish for a few weeks before introducing them to your main tank.
  3. Monitor and adjust: Regularly check your equipment and adjust as needed to maintain optimal conditions.

Troubleshooting Common Issues

Even with the best care, problems can arise in your aquarium. Here are some common issues and their solutions:

  • Algae Overgrowth: Reduce lighting, avoid overfeeding, and consider adding algae-eating fish or snails.
  • Cloudy Water: Check your filter and perform partial water changes. Bacterial blooms, uneaten food, or disturbed substrate can cause cloudiness.
  • Aggressive Fish: Rearrange decorations to break up territories and consider separating incompatible species.

Advanced Fishkeeping Techniques

As you gain experience, you should explore more advanced aspects of fishkeeping, such as breeding, aquascaping, or keeping more challenging species. These advanced techniques can provide new challenges and deepen your understanding of aquatic ecosystems.


Fishkeeping is a rewarding hobby that offers endless opportunities for learning and enjoyment. Understanding the basics and following best practices can create a beautiful, thriving aquarium that brings joy and relaxation to your home. Remember, patience and attention to detail are essential to successful fishkeeping. Happy fish keeping!


What are the best fish for beginners? Some of the best fish for beginners include betta fish, neon tetras, guppies, and corydoras catfish. These species are hardy and relatively easy to care for.

How often should I feed my fish? Feed your fish small amounts once or twice a day, only as much as they can consume in a few minutes. Overfeeding can lead to poor water quality and health issues.

How do I cycle my aquarium? Cycling your aquarium involves establishing beneficial bacteria in the tank’s filter media. This process can take several weeks and is essential for creating a safe environment for your fish.

Why is my aquarium water cloudy? Bacterial blooms, uneaten food, or disturbed substrate can cause cloudy water. To resolve this issue, check your filter, perform partial water changes, and avoid overfeeding.

How can I reduce algae growth in my tank? Limit lighting to 8-10 hours a day to reduce algae growth, avoid overfeeding, and consider adding algae-eating fish or snails. Regular maintenance and water changes also help.

What should I do if my fish are aggressive? If you have aggressive fish, try rearranging decorations to break up territories and consider separating incompatible species. Researching fish compatibility before adding new fish can prevent aggression issues.