Aquaking Aqua Heater HE-500 watt aquarium heater

The AquaKing Aqua Heater HE-500 is the largest in this range and serves tanks of 300 to 500 litres. Before ordering there is one number to check, and it is not the wattage: the thermostat starts at 22 °C and runs up to 34 °C.

What that lower limit means

You cannot set this heater below 22 degrees. For a growing space that gets cold in winter that is exactly what you want: it holds your nutrient tank at a workable value instead of letting it sink with the room. But if your aim is to keep the solution cooler than the room, no heater helps, however powerful. Warmer water holds less dissolved oxygen, and that is a problem you solve by cooling, not heating. In that case look for a water chiller instead.

Holding is not the same as heating

Five hundred watts is ample to bring a 300 to 500 litre tank up to temperature and keep it there, to within half a degree. What no heater can do is compensate for a cold room pulling heat away faster than it goes in. If your tank stands in an unheated space, insulate underneath it and cover it: that does more than a bigger heater.

The same protective sleeve

Like the smaller models it sits inside a plastic sleeve, so it can lie safely in a collapsible tank or a FlexiTank without the element touching the fabric directly. Fully submersible, suitable for fresh and salt water.

Technical Specifications:

• Type: HE-500
• Power: 500 watts
• Suits: 300 to 500 litres
• Adjustable range: 22 to 34 °C, accuracy ±0.5 °C
• Build: plastic protective sleeve, fully submersible
• Dimensions: 32 x 34 x 455 mm
• Supply: 220 to 240 volts, 50 Hz

Frequently asked questions

Can I set it to 18 degrees? No, 22 °C is the lowest setting. To go below that you need a chiller, not a heater.

Is 500 watts too much for a 200 litre tank? It will work, but the thermostat will cycle often. The HE-200 or HE-300 suits it better.

Does it really hold to within half a degree? That is the thermostat's stated accuracy. A well-mixed tank helps, so a circulation pump is a sensible companion.

Can it go in a collapsible tank? Yes, that is what the plastic sleeve is for. Keep it fully submerged.