Guest Column - September 2007
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A Balancing Act

By Robert Hedrick

Manual chemical testing technologies

A daily manual water test becomes the method of calibration for the automated system and remains important to ensure proper chemical balance.

Advances in testing technologies will allow for a water test station to be directly connected to the chemical controller. In this system a full optical water test is taken, including pH, levels of disinfectant in PPM, alkalinity, calcium hardness, total dissolved solids and temperature. The results are automatically transmitted to the Internet-based management system, which displays, in real time, a complete saturation index on the specific pool. The programmable controller can update this saturation index with pH, chlorine and temperature on a daily basis following the initial baseline complete test.

The frequency of a complete water test for alkalinity, calcium hardness and total dissolved solids may be extended to correspond to the changes in these factors, which tend to move slowly in most pools.

Phosphate removal

In the past few years, we have started to see high levels of phosphates in some pools. While the exact source is still not fully explained, there are several sources that may be contributing to these high phosphate levels. One is from the dry-cleaning industry or from the water treatment test. More information from around the industry on the frequency and number of pools that have this problem would be very helpful in determining the source of this contamination. Programmable controllers can control the time feeding of phosphate removers for those pools that are contaminated with phosphates or where phosphates are coming in from the fill water.

Internet-based data management systems

The programmable controller does not function only as a chemical controller. Any sensor or movement indicator for valves that measures any chemical perimeters or backwash valve positions or any water test factors such as flow or pressure are now reported to the Internet data management system, graphed and archived for the use of the aquatic managers' staff to better manage the aquatic facility. All information sent to the database may be downloaded to Microsoft Excel spreadsheets and saved. Proper management of the aquatic facility is more professional, accurate and informed and provides a safer environment for the bather, while at the same time reducing liability risks for the owners.

Remote control

Controllers capable of "full" bi-directional control allow for the remote calibration of the controller, changes in set points, changes in alarm perimeters, as well as making manual adjustments to the chemicals before or during competitions or even for a pre-programmed shock treatment of the pool at times when there are no bathers in the pool.

Alarms are automatically sent to all pool managers or service companies. This remote access to all pool room controls allows for correction of over 80 percent of the problems associated with chemical balance without running down to the equipment room every time an alarm goes off or dispatching a service technician to drive 50 miles just to find that all was needed was to change basic perimeters. The service company and the facility owners save money since visits to the pool room to fix problems only occur when there is actually a physical problem.

Advances in technology can provide aquatic facility managers with full information concerning their pools, a complete and real-time evaluation of what is happening to the chemical balance, and an easy method for correcting the majority of pool-related adjustments. This makes it easier to maintain chemical balance and provides a management tool that can identify problems before users are even aware of it.

The future looks bright for those who embrace these new technologies. They provide a new management tool for proper chemical balance.


Robert Hedrick is Acu-Trol's regional sales manager for the South Central region of the United States. He has extensive experience in the area of pool controllers and has been a CPO instructor since 2001. The newest member of the Pentair family, Acu-Trol Programmable Controllers is a leading manufacturer of premier pool and spa automation controllers. For more information, visit