Beginner’s Guide to Setting Up a Freshwater Aquarium

Why Start a Freshwater Aquarium?

A freshwater aquarium brings a piece of nature into your home. Watching fish glide through crystal-clear water is proven to reduce stress and create a calming atmosphere. Whether you want a small desktop tank or an impressive display aquarium, getting started is easier than you might think.

Choosing the Right Tank Size

For beginners, we recommend starting with at least a 60-litre (15-gallon) tank. Larger tanks are actually easier to maintain because the water parameters stay more stable. A common beginner mistake is starting too small — a tiny bowl might seem convenient, but it makes keeping fish healthy much harder.

Essential Equipment

Every freshwater aquarium needs a few key pieces of equipment:

  • Filter — Keeps the water clean by removing waste. Internal filters work well for smaller tanks, while external canister filters suit larger setups.
  • Heater — Most tropical fish need water between 24–26°C. A reliable heater with a thermostat is essential.
  • Lighting — Good lighting shows off your fish’s colours and is vital if you plan to grow live plants.
  • Substrate — Gravel or aquarium soil for the bottom of your tank. Choose based on whether you want live plants.
  • Water conditioner — Removes chlorine and chloramine from tap water, making it safe for fish.

Cycling Your Tank

Before adding fish, your tank needs to go through the nitrogen cycle. This process establishes beneficial bacteria that convert harmful ammonia into less toxic compounds. It typically takes 4–6 weeks. You can speed this up with bottled bacteria products or by using filter media from an established tank.

Test your water regularly during this period. When ammonia and nitrite both read zero and you have some nitrate present, your tank is cycled and ready for fish.

Best Beginner Fish

Once your tank is cycled, start with hardy, peaceful species:

  • Neon Tetras — Colourful, peaceful, and best kept in groups of 6 or more.
  • Corydoras Catfish — Friendly bottom-dwellers that help keep the substrate clean.
  • Guppies — Hardy and available in many colour varieties.
  • Cherry Barbs — Peaceful and easy to care for.

Add fish slowly — no more than a few at a time — to avoid overwhelming your biological filter.

Adding Live Plants

Live plants transform an aquarium. They absorb nitrates, produce oxygen, provide shelter for fish, and look stunning. Easy beginner plants include Anubias, Java Fern, and Ambulia. These tolerate low to moderate light and do not require CO2 injection.

Ongoing Maintenance

A healthy aquarium needs regular care:

  • Weekly 20–30% water changes
  • Test water parameters fortnightly (pH, ammonia, nitrite, nitrate)
  • Clean filter media monthly (rinse in old tank water, never tap water)
  • Feed fish once or twice daily — only as much as they can eat in 2 minutes

Visit Us for Expert Advice

At Amazonia Aquarium in Eastwood, Sydney, our team is always happy to help you get started. We offer free water testing, a wide selection of fish and plants, and honest advice based on years of experience. Drop by our store at 8 Lakeside Road or browse our online shop.