What does pH have to do with cool cell pads anyway?

PH is a simple measurement of the mineral content of water. The higher the pH reading, the more calcium and magnesium ions and other dissolved minerals it contains. 

Evaporative coolers maximize evaporation to cool the air. Since only pure water evaporates, everything else in the water is left behind. As the water recirculates, the mineral content of water increases until it forms a hard mineral deposit known as scale. Scale buildup clogs the pad opening restricting airflow and causing the pad material to become brittle.  

Dump the Sump - the pH will tell you when.

Monitor the water pH in the system with test strips or a pH meter and replace the contents when the level exceeds 8.0. A pH reading above this means the mineral content has reached the point where the scale will start to build up. Dumping the entire system is much more effective in managing mineral accumulation than continuously bleeding the system. Dumping the system weekly during hot weather when it is operating at full capacity is not uncommon. 

Flush the pads.

Maintaining adequate water flow across the pad surface to flush minerals accumulating there into the trough below is also essential. Look for dry spots on the pads and correct any plugged holes on the top distribution bar. Although more challenging to spot, look for areas of low flow along the pads that are not moving minerals into the trough. 

One more thing...but not related to pH.

An evaporative cooling system utilizing a jet pump exposes the motor to sun, rain, and dust. If you think about it, a cool cell jet pump is one of the few motors on a farm that is left entirely out in the elements. Consider adding an inexpensive cover like the unit pictured above to protect the motor. This universal cover, constructed of HDPE plastic, will help increase the motor's working life.