An aquarium is one of the most beautiful corners you can create at home – a piece of living nature that calms and never bores. Yet most beginner disappointments happen in the first two weeks, because fish are added too soon. This guide takes you from shopping to your first fish in the right order.
- Start with a 54–100 litre tank – bigger is more stable.
- Before any fish, the tank must run empty for 3–6 weeks (nitrogen cycle).
- Core equipment: filter, heater, light, substrate, test kit and live plants.
- Maintenance: 20–30 minutes a week.
1. A bigger tank is easier, not harder
The most common misconception is that a small aquarium is simpler. The opposite is true: in a larger volume of water, swings in temperature and quality are slower, so mistakes are forgiven more easily. Think of a cup of tea and a bathtub – the cup cools in minutes, the tub stays warm for hours. The same applies to everything that can go wrong in a tank.
For a start we recommend a 54–100 litre tank (standard length 60–80 cm) – big enough for stability, small enough for manageable maintenance. Leave nano tanks under 30 litres to the experienced.
2. What you need: the shopping list
- an aquarium with a lid (54 l or more) and a cabinet or solid base – a full tank weighs over 70 kg,
- a filter sized for the tank (internal for smaller, external for 100+ l),
- a thermostat heater (roughly 1 W per litre) and a thermometer,
- lighting (often built into the lid) on a timer, 8–10 hours a day,
- substrate: 2–3 mm gravel or a nutrient base for plants,
- a water conditioner (removes chlorine) and a test kit for ammonia, nitrite and nitrate,
- roots, stones and live plants – not decoration but the tank's cleaning crew,
- a bucket, a gravel siphon and a net – used only for the aquarium.
3. Setting up step by step
Place the tank away from direct sun (algae!) and radiators. Rinse the substrate and add 4–6 cm, sloping gently towards the front glass – debris slides forward where it is easy to siphon. Position roots and stones, plant the plants (tall at the back, low at the front), then pour water in slowly over a plate so the bottom is not stirred up. Add the water conditioner and switch on the filter and heater (24–25 °C).
For the first few days the water may turn cloudy – a normal bacterial bloom that clears on its own. Do not panic-change the water.
4. The most important step: a fishless start
A new aquarium is biologically dead – the filter holds none of the beneficial bacteria that convert toxic ammonia from fish waste into less harmful nitrite and then nitrate. This process (the nitrogen cycle) takes 3–6 weeks. During this time the tank runs without fish; tests show ammonia and nitrite rise and then fall to zero. Only then is the aquarium ready.
5. The first fish
Add fish gradually, one shoal every week or two, so the bacteria adapt to the growing load. Before buying, check that the species match in temperature, water hardness and temperament. We have collected the most rewarding starter species in the guide 10 best aquarium fish for beginners – from the hardy White Cloud minnow to lively guppies. The full species overview is in our aquarium fish directory.
6. Weekly maintenance
A settled tank needs only 20–30 minutes a week: a 20–30 % water change with gravel siphoning, cleaning the glass and occasionally rinsing the filter media in drained aquarium water – never under the tap, as chlorine would kill the beneficial bacteria. Feed moderately: what the fish eat in two minutes, once or twice a day. Leftover food only pollutes the water.
Frequently asked questions
Can I use tap water?
Yes, with a water conditioner that neutralises chlorine and heavy metals.
How much does it all cost?
A solid starter kit (54–60 l tank with equipment) starts at roughly €100–150; fish and plants are the cheapest part.
Do I need CO₂ and fertilisers?
Not at the start – choose undemanding plants (anubias, Java fern, vallisneria) that thrive without additives.
The article is just the start. Care for your pet every day. 🐾
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