The short answer
Put your aquarium out of direct sunlight, away from radiators and draughts, and on solid furniture that can take the weight — ideally near a power socket. Aquariums hate rapid temperature change, and where you place the tank decides how stable it is and how much algae you fight. Choose the spot before you fill it, because a full tank is almost impossible to move.
What to avoid
- Direct sunlight: the number one cause of algae and overheating. Even a few hours of afternoon sun on the glass triggers green water.
- Radiators and heat sources: they cause temperature swings the heater can’t keep up with.
- Draughty spots: doorways, hallways and cold external walls chill the tank unevenly.
- High-traffic areas: constant vibration and knocks stress fish.
What you want instead
A stable, shaded corner on solid, rated furniture, near a socket for the equipment, with a little room behind for filter pipework and above for maintenance. Steady room temperature and gentle indirect light make for the easiest tank.
Getting the weight right
Bigger tanks need a floor that can bear them. Over a suspended wooden floor, position a large tank across the joists or above a load-bearing wall rather than in the middle of a span. See how heavy a full aquarium is and, once sited, how to set it up. Browse tanks on the aquariums hub.