How to Treat Water in a Swamp Cooler

Andrew Mayfair J.D.

An evaporative cooler, often referred to as a "swamp cooler," is an air conditioning alternative that uses a water pump and water-soaked padding in a boxed frame to channel and cool outdoor air through a fan that delivers the cooled air indoors. It is most functional and healthy in dry, non-dusty and unpolluted atmospheres. However, these coolers must be properly maintained and treated for mineralization and the proliferation of bacteria and fungi that can occur in the water supply.

  1. Consult your Owner's Manual prior to any treatment to review the maintenance and treatment guidelines recommended by the manufacturer.

  2. Turn off and unplug the cooler unit. Turn off the water supply and drain the cooler unit via the drain plug.

  3. Clean the water tank by rinsing it with mild, soapy water and drain the cooler unit via the drain plug. If recommended by your Owner's Manual, place water treatment tablets and/or zinc anodes in the water pan to control corrosion, mineralization, and bacterial and fungal contamination.

  4. Refill the cooler unit's water supply, reassemble the cooler unit and restart the system.