Your first aquarium: what you actually need

A larger tank is usually easier than a small one. In more water, waste is diluted and temperature and chemistry shift more slowly. For a beginner 60–120 litres is a good zone; smaller tanks are fine, they just need more attention.

Measure the spot before buying. Water is heavy (a litre is about a kilogram), so the stand must be level and sturdy.

A tank with a lid, a filter, a heater with thermostat for tropical fish, a thermometer, substrate (sand or fine gravel), a tap-water conditioner for removing chlorine, and a test kit for ammonia and nitrite.

Lighting is needed if you have plants, and to see the fish. Decoration (wood, caves) is pretty and often helps fish feel secure.

CO₂ systems, expensive lighting and “fixes-everything” liquids are not needed on day one. First learn to keep the water stable; everything else is an add-on.

Set it up, fill with water, add the conditioner, switch on filter and heater, then cycle the tank (see the next guide). Fish come only when the water is ready, not the same day.

Later: regular partial water changes. Many aquarists do about 20–30% weekly; it depends on stocking and tank size, so adapt it.