Upside down pad
One of the keys to minimize minerals on evaporative cooling pads is to insure proper water flow over the surface of the pad. The greater the amount of water flowing over the surface of the pad the harder it is for minerals to build up on pad surfaces. In this picture you can see how installing a 6" pad with 45 X 15 flute angles upside down affects mineral build-up. A properly install 45 X 45 flute angle pad increases water flow on the outside surface of the pad (45 degree angle sloping downward from inside to outside) which tends to keep the surface of the pad free of minerals and dirty. When installed upside down water flowing over the outside surface is significantly reduced and as a result minerals tend to build up relatively quickly.