1. Choose the Right Aquarium Size

While small tanks may seem easier, larger tanks are actually more stable and forgiving for beginners.

• For a single fancy goldfish, we recommend at least 120 litres just remember this will need upgrading as your fish grow (goldfish grow larger than most people assume).
• For common or comet goldfish, 200+ litres is ideal as they grow quickly.
• Always allow plenty of swimming space and surface area for oxygen exchange.

2. Pick Suitable Equipment

Coldwater fish still need filtration and good water movement.

• Filter: Use an internal or external filter sized for your tank volume.
• Lighting: A low-heat LED light helps plants thrive and enhances viewing.
• Air pump: Increases oxygen and prevents stagnant water.
• Gravel or substrate: Rinse before use to keep the water clear.

3. Add Décor and Plants

Choose smooth ornaments and silk or live plants to create hiding spots and enrichment. Avoid sharp edges that could damage fins. Hardy live plants like Anubias, Elodea, and Java Fern can thrive in cooler water.

4. Fill and Treat the Water

Always use dechlorinator before adding water to the tank. Chlorine and chloramine in tap water can harm fish and beneficial bacteria.

5. Cycle the Aquarium

Before adding fish, your aquarium must go through the nitrogen cycle. This process builds up beneficial bacteria that break down fish waste (ammonia and nitrite) into safer nitrate.
👉 Learn more in our How to Cycle Your Aquarium guide

6. Introduce Fish Slowly

Once your water tests show 0 ammonia and 0 nitrite, you can begin adding fish. Start with just a few and increase numbers gradually to avoid stressing the biological filter.

7. Regular Maintenance

Perform weekly partial water changes (25–30%) and clean filter sponges in old tank water (never tap water).