A fish aquarium can be one of the most rewarding things in your home or office — but only if it’s set up properly from the start. Most problems people run into later come from rushing the setup or skipping steps that seem minor but actually matter.
Here’s what you need to know before you add your first fish.
Start With the Right Tank Size
The most common mistake new owners make is going too small. A smaller tank seems easier to manage, but the opposite is true — water parameters in a small tank swing much faster and there’s less room for error. A 60–80 litre tank is a much better starting point for most beginners than a nano tank.
The Equipment That Actually Matters
A healthy fish aquarium runs on three things:
- A filter — the most important piece of equipment. It removes waste and houses the beneficial bacteria your tank depends on. Don’t undersize it.
- A heater — if you’re keeping tropical fish, water temperature needs to stay stable. Fluctuating temps stress fish more than most people realise.
- A light — for fish health and plant growth if you’re going planted.
Everything else is secondary. Get the fundamentals right before buying extras.
Cycle the Tank Before Adding Fish
This is the step most people skip because it takes time — and it’s the main reason beginners lose fish in the first few weeks.
The nitrogen cycle is the process where beneficial bacteria establish inside your filter. These bacteria convert ammonia (from fish waste) into less harmful compounds. Without them, ammonia builds up fast and fish die.
Run the tank for at least one to two weeks before adding any fish. Test the water before you stock it.
Choose the Right Fish
Not all fish get along. Some species are aggressive, some need soft water, and some grow far larger than they look in the shop. Do your research before buying.
For beginners, hardy fish like tetras, danios, or guppies are a good starting point — they’re forgiving of minor water quality issues while you’re still learning. Add fish slowly, a few at a time with a week or two between additions. This gives your filter time to adjust without getting overwhelmed.
Keep It Consistent
The tanks that run the best are the ones that stay consistent. Regular water changes (around 20–25% per week), sensible feeding, and a reliable filter handle most problems before they start.
If you’re in Melbourne or Narre Warren and want your fish aquarium set up properly from day one, Aquatics by Ash can handle everything — setup, stocking advice, and ongoing maintenance so you can just enjoy it.