Place it where water or air can circulate and follow the manufacturer’s directions. A heater must be fitted according to its minimum water-level marking before being switched on.

Use a separate thermometer and check regularly, especially during the first day after installation or adjustment. Avoid rapid temperature changes.

Match capacity and purpose to aquarium volume, room temperature and livestock. Oversized or poorly placed equipment can produce uneven temperature.

Switch off electrical heating equipment and let it cool before lowering the water. Restart only when correctly submerged again.