Fish Tank & Aquarium Heaters

Choosing the right heater comes down to matching its wattage to your tank's size - too weak and it will struggle to maintain temperature in colder months, too powerful and you risk overheating during warmer spells. As a general rule, allow around 1 watt per litre for a room kept at normal household temperature, though unheated rooms or larger tanks may need more. If you're unsure how many litres your setup holds, our fish tank volume calculator makes it easy to work out the right size before you buy. Once fitted, a good heater runs quietly in the background, keeping conditions stable for your fish so they can thrive without the stress of fluctuating temperatures - giving you one less thing to worry about day to day.