An apparatus and method for blending fluids and applying the blended fluid to a surface of an aircraft during deicing and anti-icing operations having a first tank, second tank, blend tank, pumps, conduits, heaters, controllers, and a delivery device. In operation, a controller compares the composition of the blended fluid in the blend tank to the composition of a target fluid that is determined by current ambient temperature of the environment, and advances first and second fluids from the first and second tanks, respectively, into the blend tank to achieve and maintain the target fluid composition in the blend tank.