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The Science Behind Pool Cleaning

Best Practices for Robotic Pool Cleaners in Commercial Pools

By Richard K. Cacioppo Sr., J.D.


Pool cleaning, namely brushing and vacuuming, is a science, not an art. A pool (i.e., the water) is like a living thing as it constantly changes. Beyond the water and the supporting structure, every pool is composed of millions of living and non-living organisms. Some are innocuous, while others are deadly. Pool water is exposed to every change in the surrounding environment—from temperature and humidity to wind and precipitation, but most of all, bather loads. Indoor pools are less affected by weather and the surrounding environment, but are still affected by their own surroundings as they are restricted to a confined space. It is almost like a reverse process. What is in the pool water evaporates into the air in the indoor space and is inhaled by bathers and pool personnel.

Pool operators have a responsibility to their employers and, most importantly, bathers who use the pool (and spa) facility. An improperly cleaned pool is a breach of responsibility. This can result in financial losses to the organization, and possibly even criminal prosecution.

Failure to properly clean a pool allows dangerous contaminants to remain in the water or even evaporate into the air after it passes through the pool's circulation system. In fact, there is a misconception that most filtration systems will sufficiently remove all contaminants from the pool. However, this is not the case and there are several problems with relying solely on the main pump and filter:

  • Filter systems do not clean the entire pool. They primarily draw water from the surface and pool floor. Debris and contaminants that adhere to the walls, floors, corners, and other parts of the pool's vertical structure are filtered only when they initially enter the water.
  • Filter systems do not brush and/or vacuum the pool. The walls, steps, floor and hard-to-reach areas of the pool must be continually brushed to release contaminants into the water, where dirt, leaves and even microscopic debris are then sucked into the skimmers or into the floor drains after settling to the bottom of the pool, almost always in the deep end.

Most pools, when they are being used during the day, are not properly maintained—other than those with state-of-the-art automatic controllers that help pool operators monitor and correct water imbalance, sanitation, lights, pumps, heaters, modes (between spas and pools) and valve actuators. Even the most responsible pool operators monitor proper sanitation no more than a few times per day, some at far greater intervals. In the summer, when bather loads hit peak levels, most pools operate at least 12 hours per day. It is during this time that they are rarely cleaned. Between regular sanitation checks and any corrective measures, bathers can be exposed to whatever is floating in the water or attached to the pool's walls, steps and floors, as well as any cracks, crevices and corners.

Manual Brushing Is Inadequate

It is virtually impossible to manually brush the entire surface of a pool (i.e., walls, floor and other areas) on a regular basis as there is simply too much area to cover. Further, even if it were possible, workers are limited to what they can see, and in most cases, if any area of the pool appears to be dirt-free, it likely will not be cleaned. Pool cleaning is one of the three main disciplines of proper water hygiene, the other two being sanitation and filtration.

Robotic Pool Cleaners: Past, Present and Future

As noted in the book, "A Brief History of Pool Cleaners," the first pool cleaner was patented in the United States and the first major investigation into pool hygiene was addressed by the American Public Health Association (APHA) in the same year, 1912. Thereafter, the organization started creating reports and proposals to develop laws and guidelines for proper pool hygiene and safety. In September 2014, the CDC released the long awaited Model Aquatic Health Code (MAHC).

Commencing in the APHA's first official report in 1921, which was issued in narrative form by its Joint Committee of Safety Engineers, and continuing through 1984, nine additional reports were issued. In almost each case, it was highly recommended that all commercial pools should use pool vacuums on a regular basis.

A current study being conducted in Canada and the United States by the Center for Public and Lodging Pool Study (CPLPS) has revealed many pools at the most elite hotels and resorts are way behind the times as it comes to pool maintenance. The study estimates only 1 percent of all of these facilities currently use robotic pool cleaners, while the remaining opt to clean their pools manually.

Fairmont Hotels & Resorts, a Toronto-based operator of luxury hotels and resorts, has been invited to participate in the CPLPS study and being offered a complimentary high-end robotic pool cleaner as well as a handheld pool and spa commercial vacuum, which are ideal for commercial pool operators and service professionals who manage both public and private pools.

As a result, several other facilities have proactively started to incorporate robotic pool cleaners into their pool maintenance routines.