Abstract: An improved process for cleaning heat exchanger tubes using propellant water to shoot pigs, brushes, scrapers, or similar devices through the heat exchanger tubes. The improvement includes adding treatment chemicals individually or in combination to the propellant water so that corrosion, mechanical wear, or scaling of the heat exchanger tubes are controlled. The treatment chemicals include, but are not limited to, ferrous sulfate, sodium hypochlorite, or hydrogen peroxide. Other chemicals, such as, oxidizers, reducers, acids, bases, inorganics and organics when added in sufficient concentration will reduce heat exchanger tube corrosion, mechanical wear and scale.