Sunbeam KE0100 Liquid Descaler 250ml for Coffee Machine/Kettle $5 + Delivery ($0 with Prime/ $59 Spend) @ Amazon AU

Cheap descaler deal is back. Yes, this is basically citric acid. You can also buy citric acid and use that, but for some people this might be more convenient.

• For all coffee makers and kettles.
• Removes scale build up to restore the efficiency of your appliance.
• Prolongs the life of your appliance