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.

Routine Robotics

Robotic pool cleaners can be easily incorporated into the protocol of any medium-to-large aquatic facility. Their operation is simple: plug it in, program the unit for coverage and length of operating time, and drop it in the water. For example, a typical YMCA pool might be 23 meters long, have more than 87,000 gallons of water, and see heavy usage in terms of swimming lessons, water aerobics, swim meets and other programs. At the end of the day, after all swimmers have left, the facility manager/operator starts the daily pool cleaning regimen—in compliance with provincial health codes—before the pool can be reopened the next day.

The daily closing routine typically involves testing and treating the water. However, one of the latest best management practices (BMPs) used by facility managers is to start the pool cleaning routine by placing a robotic cleaner into the pool first, before performing any other maintenance.

Alex Sutherland, a certified pool operator (CPO) and director of facility services for Family YMCA in St. Thomas, Ontario, now has his staff begin their normal pool closing routine by plugging in a robotic cleaner and placing it in the center of the pool first. In one of the United States' grand hotels, The Homestead in Warm Springs, Va., managed by a property management company that specializes in ultra-luxury hotels and resorts that has numerous pools and even a lazy river, an hour after they are closed, the manager directs a staff of many employees to spend hours manually cleaning them. This is the rule, not the exception in most lodging facility pools.

"We started using robotic cleaners three years ago when regulations changed and we could no longer use our suction-side cleaning system due to the potential risk of entrapment," said Sutherland, whose facility is open 16 hours a day, 364 days a year. "Before we started using robotic cleaners, the 25-meter pool was manually vacuumed three times per week, taking approximately two hours each time, and we didn't necessarily get every square inch of the pool either."

By using a robotic pool cleaner, Sutherland feels like he has hired a worker who continually cleans the pool seven to eight hours every night without taking breaks. That said, robotic cleaners are programmable to run any length of time, and most aquatic facility operators leave the unit in the pool to operate overnight. Once it has completed its cleaning cycle, the unit should be removed from the pool, drained and stored for the next day's use.

According to Richard Deakin, commercial project manager at Hollandia Pools in Toronto, most of his customers have started to incorporate the use of robotic cleaners into their regular maintenance as well.

"Our customers tend to be those who are proactively working to ensure the highest water and air quality at their facilities—above and beyond what is dictated by the board of health," Deakin said. "Robotic cleaners are just another tool to ensure the cleanest pool possible using today's technology, in addition to ultraviolet (UV) light, chemical controllers, etc."

Another benefit of robotic cleaners is that at times, commercial pools can become so dirty that they require more than one full cleaning. Therefore, a nice feature to look for in a robotic cleaner is a "time delay" option, which allows the user to set the cleaner to start again three to five hours after completing the first cleaning. This allows any dirt that has been lifted to settle back down to the pool floor to be picked up on the second pass.

"The robotic cleaner has become central to our entire system of cleaning," said Sutherland, who owns two units, just in case one fails for any particular reason. "A robotic cleaner is a piece of equipment just like any other, which needs belts, cords and other parts that may need to be changed or repaired. We can no longer survive a day without our robotic cleaner, so having a backup unit allows us to always be prepared."

On another note, by eliminating the time-consuming task of manually cleaning the pool, a robotic pool cleaner can provide a service professional with additional time to work on other aspects involved in maintaining an aquatic facility. "We have gained six-plus hours for pool maintenance, which I have redirected to have our staff clean the change rooms at our facility," Sutherland said. "We understand that first impressions are important, and we want to be sure our customers always come into a clean change room every morning. Further, staff can now also focus on water chemistry, pool safety checks and general interaction with customers. Plus, the cleaner the pool is keeps customers happier and healthier."

Benefits of Using Robotic Pool Cleaners

  • No skill or training is required. Computerized guidance system does all the work.
  • Saves effort and labor. Simply plug it in and set the program and timer.
  • Efficiently covers up to 99 per cent of the pool floor.
  • Robotic pool cleaners travel up to 22.2 meters per minute (73 fpm), which is much faster than manual cleaning.
  • Cleans, brushes and filters simultaneously. The rotating scrubbing brushes are made of durable, absorbent materials.
  • Quickly removes debris (e.g., dirt, sand, leaves, insects, hair, pebbles, etc.), and breaks up and removes algae and bacteria.
  • Reduces energy/electricity costs.
  • Smoothens surfaces and helps to preserve concrete pool finishes.
  • Certified safe with no chance of shock or injuries to operators or bathers.
  • A robotic cleaner can pay for itself approximately two years after it is incorporated into an aquatic facility's maintenance regime.
  • Manufacturers offer different plans to aquatic facilities for leasing and/or purchase options.

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