Introduction to Fish Keeping: Essential Basics Every Beginner Should Know
Introduction
Fish keeping is one of the most rewarding and relaxing hobbies you can begin, but it also requires preparation and understanding to ensure long-term success. Whether you're getting ready to set up your first aquarium or upgrading your current one, knowing the fundamentals of tank setup, water chemistry, filtration, and species compatibility is key to keeping your fish healthy and stress-free.
This guide outlines the core essentials that apply to most freshwater fish. Think of it as an overview of the basics—an introduction to the equipment and knowledge you’ll need before adding animals. This is just an overview of what most fish will need; we will be sharing specific care guides for individual species soon, but for now, these basics will help you get started on the right path.
Choosing the Right Aquarium Size
The size of your tank is one of the biggest factors in your success. Larger tanks are more stable and forgiving, especially for beginners. Small tanks can fluctuate in temperature and water quality very quickly, often leading to stress or illness in fish.
There are also many affordable options for doing water changes on larger tanks, so physical maintenance isn’t nearly as hard as the traditional bucket method—larger tanks can be just as manageable as smaller setups with the right equipment.
Tips for selecting a tank size:
Research the adult size of any species you plan to keep.
Avoid mixing incompatible species in small spaces.
When in doubt, go bigger—it’s easier and more stable.
A 40–60 litre tank is a great starting point for most beginners, depending on the species you choose.
Filtration: The Heart of the Aquarium
A good filter is essential for keeping fish healthy. Filtration handles waste, supports beneficial bacteria, and keeps the water clear.
Common filter types include:
Sponge filters — gentle, great for small tanks and shrimp.
Internal filters — suitable for small to medium aquariums.
Hang-on-back filters — great all-rounder for medium tanks.
Canister filters — best for larger setups and heavy stocking.
Make sure your filter can handle at least 4–6x the tank’s volume per hour for best results.
Heating & Temperature Stability
Are you keeping cold water fish or tropical fish? While “tropical” may sound fancy, it simply means fish that need a heater and warmer temperatures. Cold water species are honestly the trickiest here in Queensland, Australia, and require extra care.
Stable temperatures are critical: fluctuations cause stress, which weakens immune systems and can lead to disease. Always use a thermometer to monitor your water accurately.
Understanding Water Quality & The Nitrogen Cycle
If there’s one piece of information you absolutely cannot skip or cut corners on, it’s cycling your tank and learning the nitrogen cycle. This is without a doubt the most important aspect of keeping fish and the most unforgiving if done incorrectly.
The nitrogen cycle allows beneficial bacteria to convert harmful waste into safer compounds:
Ammonia (toxic)
Nitrite (toxic)
Nitrate (less toxic)
A properly cycled tank is essential before adding fish. Mistakes here have far worse consequences than slightly incorrect tank sizes or subpar diets. Testing ammonia, nitrite, and nitrate levels regularly ensures your aquarium stays safe.
Setting Up Substrate & Aquascaping
Your choice of substrate and decorations influences both the look and function of your aquarium.
Substrate options:
Sand — waste generally stays on top; ideal for bottom-dwellers. Vacuuming should be done carefully to avoid disturbing plants.
Gravel — debris can collect between stones, making vacuuming effective.
Aquasoil — perfect for planted tanks; avoid gravel vacuuming as it can turn your tank into a muddy mess.
Add rocks, wood, and plants to provide hiding spaces and reduce stress. Live plants also improve water quality by absorbing excess nutrients.
Feeding Your Fish
Different fish have different dietary needs, but a balanced, varied diet is key to long-term health.
Feed roughly the size of the fish’s eye per feeding for individual species like bettas or dwarf cichlids.
Community tanks may require slightly different portions, as multiple fish will snatch food quickly.
Offer a mix of flakes, pellets, frozen, or live foods depending on species.
Overfeeding is harmful, but the risks depend on species and tank setup.
Routine Maintenance
A clean and stable environment helps prevent illness and stress. Maintenance will depend on your tank type:
Aquasoil tanks: avoid gravel vacuuming; it can disturb plants and muddy the water.
Gravel tanks: vacuuming works well to remove debris.
Sand tanks: waste generally stays on the surface; gentle siphoning is sufficient.
Other general tasks:
Weekly/fortnightly water changes (20–40%)
Rinse filter media in tank water only—never tap water
Clean glass and remove algae
Choosing Compatible Fish
Not all fish can live together peacefully. Consider:
Adult size (not just juvenile size)
Temperament (aggressive vs peaceful)
Schooling requirements
Temperature and water parameter needs
Planning your stock list in advance prevents problems later.
Conclusion
There’s a lot to learn at the start, but in practice, it’s a lot easier to understand than it seems. Spending the time to really understand and research the information in this guide will take you down one of the most fulfilling journeys of your life.
Fishkeeping isn’t just a hobby or keeping a pet—it’s a beautiful world of colour and growth. Some days it’s incredibly therapeutic. While we all know animals can have calming and stress-relieving benefits, aquariums take it to the next level. That’s why fish tanks are often placed in hospitals and dental offices: to secretly calm your body and mind before your turn.
With the right approach, fishkeeping provides both relaxation and a sense of accomplishment that few other hobbies can match.
Ready to dive deeper? Explore our other care guides, including our dot point style checklist to see if fishkeeping is right for you, our in-depth general guide, and stay tuned for our future species-specific guides to help you create the perfect aquarium for your fish.
