Automation. This is the word used to describe the fancy, flashy and functional box that hangs on the pump-room wall to regulate the pool’s chemical feed. It seems to attract pool operators more than any of the pumps, feeders, filters and pipes that also populate the room. But it’s not simply an “automatic” device that works when it’s turned on and stops when it’s shut off. The pool’s electronic controller is smarter than that.
Similar to an automatic thermostat, automation requires a desired value to be chosen by the operator; this will allow the pool systems to run until that target is met. Those magical “set points” are determined by the operator’s wisdom based on the test results from a high-tech test kit.
To achieve these desired values in your pool water, the controller itself has relays that turn pumps on and off while reading the results of the chemical feed demanded. When the water values match the chosen set-level, the unit turns the pumps off.
The state-of-the-art controllers found in modern pump rooms sometimes manage half-a-dozen chemical targets, but only two are critical to manage: pH and ORP. These are the two most important variables in pool water and, without rather constant vigilance, they also move the fastest to unacceptable levels.
ORP, sometimes called the “work value” of the chlorine (or another sanitizer) must be maintained constantly for safe, clean water. The pH, the acid/base-relationship number at the heart of our “water balance,” assures the function of the ORP, maximizes sanitation and oxidation and maintains nonaggressive water so the pool and its parts will be around for future seasons.
Ultimately, managing pH and ORP via “automation” is a qualitative thing. We control set points, and measure and modify the results produced by whatever it is that we’ve chosen for our controller to demand, not the quantity or level of the chemical itself.
Unlike other pieces of the pool system, once the controller is installed, it basically needs little or no care other than confirmation that the readouts are accurate. Manual test-kit readings should be taken daily to confirm the digital values shown on the controller are correct. Simple calibration adjustments should made if deemed necessary, though small corrections are not wise: You could end up fiddling with the calibration all day, with the pool-water results varying only slightly.
While the calibration of a controller shouldn’t vary to any extreme, once shut down for the off-season, the device should start up for the new swim season with little or no adjustments. Annual values for set points do not change; if they were well chosen last year, they are fine for this one.
Relating to the above “calibration,” too much emphasis on precision can drive an operator to drink because simple set-level adjustments can handle the small, yet desired, changes.
One issue that can occur is electronic failure. If your controller doesn’t measure or react, maybe some “fixin’” is necessary. Replacement circuit boards and parts for old units are intentionally harder to find, but keep looking!
Automation devices rarely need replacing; even 30-year-old controllers have been known to run just fine. However, sometimes it can be wise to upgrade an aging controller with a newer unit deemed simpler or more high-tech. Features such as newer sensing probes and wireless remote readings may be reasons to consider newer automation systems.
However, don’t get so caught up in the bells and whistles that you lose sight of the main functionality. It's reasonable to wonder which variables we can control with the very best of automation. Those fancy boxes found in modern pump rooms sometimes manage half-a-dozen chemical targets, but, as mentioned earlier, only two — repeat two — are critical to manage. They are, of course, pH and ORP. They not only are the two most important variables in pool water, but they also move the fastest to levels we don’t want to see without rather constant control. Control them with automation.
About the Instructor
Kent Williams has taught the Certified Pool Operators course for 22 years; more recently, he wrote NRPA’s Aquatic Facility Operator textbook and its training program, teaching the AFO course from Sacramento to Hong Kong. Williams is founder and executive director of the Professional Pool Operators of America, and writes and publishes the popular Pumproom Press for members. The PPOA Website features many of his writings.