By Brett Holland, Treasure Pools /  brett@treasurepoolsfl.com

 It is 2018 and the demand for ozone is continuing to rise for residential swimming pools.  Consumers and industry professionals are both becoming more aware of the downsides of traditional sanitizers, such as salt chlorine generators, liquid chlorine and stand-alone tablet feeders. 

Ozone was first discovered 170 years ago, and then in 1937 the first ozone system was introduced into a commercial pool in the United States.  Since then, ozone has been mandated for use of all Olympic training and competition swimming pools, due to its disinfection and oxidation capabilities.  Ozone can change the molecular structure of organic and inorganic compounds, destroy them completely, and allow them to be easily removed from the water by the pool filter.  These compounds (sweat, urine, body oils, lotion, saliva, etc.) are what causes red/irritated eyes when combined with chlorine.  Traditional sanitizers, such as salt systems are not an effective alternative if you wish to eliminate these chlorine by-products also known as chloramines. 

Unfortunately, there is little to no knowledge by most industry professionals when it comes to sizing a proper ozone system.  Due to this, there has not been much success (unless you know how to properly size one).  Ozone is often presented as a cure-all, however typically undersized.  Whether you are a builder or a service professional that would like to offer your customers the cleanest, clearest water available in today’s industry, there are a few factors in sizing your ozone system I suggest you consider.

The three big factors for an ozone system are:  The output of the generator (Grams per hour/gph), contact tank, and oxygen concentrator.  I am going to provide you with a formula on the gph needed for your project at the end of this article.  Most common ozone systems produce (.5 gph-1.12 gph) and do not have a contact tank.  Some units have a mixing vessel which has minimal contact time, 20 seconds at best.  The most common size contact tanks I use are between 30-40 gallons and on average provide 4-7 minutes of contact time.  Oxygen concentrators are imperative here in Florida due to the moisture in the air.  They are important with corona discharge systems because without them you will have nitric acid build up within the unit.  This happens when moisture from the air (unfiltered ambient air) is struck with the electrical arc from the corona discharge.  This will cause premature failure of the ozone generator and require frequent unnecessary maintenance. 

Ozone dosage rates: Rates will vary from 0.1 – 0.5 ppm based on conditions such as:  water temperature, indoor/outdoor pool or spa, covered or uncovered, bather load, filtration type and chemical-use reduction.  I recommend using 0.5 ppm due to most Florida pools being uncovered and having a high water temperature.

Calculating the water shape’s flow rate:  Volume/360 minutes (six-hour turnover) = full flow gpm.
Example: 15,000/360 minutes= 41.7gpm
Ozone Output required, gph (grams per hour)
*Note that 0.228 is a multiplier used to calculate pounds per day of ozone to gph.  This is a fixed value.
Example: 0.5ppm ozone x 41.7 gpm x .0.228 = 4.75 ozone gph

Calculating the ozone loop flow rate:  The ozone loop flow rate will range from 15 – 30% of the full flow gpm, 20% is typical.
Example:  41.7 gpm x 20%= 8.34 gpm

Calculating the contact time divide the volume of the tank by the SS flow rate:
Example:  30 gallon tank/8.34 gpm= 3.59 minutes
*Calculating the CT value (concentration multiplied by Time) is based on the SS flow rate.

 As you can see on a standard 15×30 pool here in Florida, there is approximately 4 gph needed of ozone.  If the goal in your project is to get a maximum chemical reduction, a unit that produces between 0.5 – 1.12 gph will not meet your required ozone output.

I hope this article helps you when sizing your next ozone system.  If you have any questions please feel free to email me, and I will be happy to assist you with your project.

 References:
1.  Marc Debrum, “Ozone is Not Just for Residential Potable Water Treatment”, 2010
2. Marc Debrum, “The Ultimate Swimming Experience”, 2014

The scholarship application for the 2018-2019 FSPA Scholarship Program is ready!  Dependents of owners or company employees (of 2+ years) are welcome to download the application.  All materials are due in the office by June 29.  Spread the word to any company staff with graduating high schoolers or college students.

A situation a Florida business ran into recently made us believe that a short article on this subject might be of value.  The US Department of Labor contacted this business as a result of a former employee complaint.  The individual was a pool service technician who was paid per pool serviced vs. by an hourly wage.  When the Department of Labor contacted the business they asked for copies of the employer records demonstrating hours worked, etc.

The employer explained how the technicians were not paid hourly, how the hourly wage equated to well above minimum wage and that none of his technicians worked overtime (in fact they often worked far less).  Still, the failure to have detailed records on how many hours each employee worked was a failure in compliance according to the department.

Below are some of the basics on FLSA.  The Fair Labor Standards Act (FLSA) establishes minimum wage, overtime pay, recordkeeping, and child labor standards affecting full-time and part-time workers in the private sector and in Federal, State, and local governments.

Nationally, nonexempt workers are entitled to a minimum wage of $7.25 per hour effective July 24, 2009.  Florida has a $8.25 minimum wage.  Nonexempt workers must be paid overtime pay at a rate of not less than one and one-half times their regular rates of pay after 40 hours of work in a workweek.

Workweek – A workweek is a period of 168 hours during seven consecutive 24-hour periods. It may begin on any day of the week and at any hour of the day established by the employer. Generally, for purposes of minimum wage and overtime payment, each workweek stands alone; there can be no averaging of two or more workweeks. Employee coverage, compliance with wage payment requirements, and the application of most exemptions are determined on a workweek basis.

Hours Worked – Covered employees must be paid for all hours worked in a workweek. In general, “hours worked” includes all time an employee must be on duty, or on the employer’s premises or at any other prescribed place of work, from the beginning of the first principal activity of the work day to the end of the last principal work activity of the work day.  Also included is any additional time the employee is allowed (i.e., suffered or permitted) to work.

Some employees are exempt from the overtime pay provisions or both the minimum wage and overtime pay provisions.  Because exemptions are generally narrowly defined under the FLSA, an employer should carefully check the exact terms and conditions for each.  Detailed information is available from local WHD (Wage and Hour Division) offices.  Following are examples of exemptions which are illustrative, but not all-inclusive.  These examples do not define the conditions for each exemption.

Exemptions from Overtime Pay

1. Certain commissioned employees of retail or service establishments; auto, truck, trailer, farm implement, boat, or aircraft sales-workers; or parts-clerks and mechanics servicing autos, trucks, or farm implements, who are employed by non-manufacturing establishments primarily engaged in selling these items to ultimate purchasers;
2. Employees of railroads and air carriers, taxi drivers, certain employees of motor carriers, seamen on American vessels, and local delivery employees paid on approved trip rate plans;
3. Announcers, news editors, and chief engineers of certain non-metropolitan broadcasting stations;
4. Domestic service workers living in the employer’s residence;
5. Employees of motion picture theaters; and
6. Farmworkers

Recordkeeping
The FLSA requires employers to keep records on wages, hours, and other items, as specified in DOL recordkeeping regulations. Most of the information is of the kind generally maintained by employers in ordinary business practice and in compliance with other laws and regulations. The records do not have to be kept in any particular form and time clocks need not be used. With respect to an employee subject to the minimum wage provisions or both the minimum wage and overtime pay provisions, the following records must be kept:

1. Personal information, including employee’s name, home address, occupation, sex, and birth date if under 19 years of age;
2. Hour and day when workweek begins;
3. Total hours worked each workday and each workweek;
4. Total daily or weekly straight-time earnings;
5. Regular hourly pay rate for any week when overtime is worked;
6. Total overtime pay for the workweek;
7. Deductions from or additions to wages;
8. Total wages paid each pay period; and
9. Date of payment and pay period covered.

Records required for exempt employees differ from those for nonexempt workers. Special information is required for homeworkers, for employees working under uncommon pay arrangements, for employees to whom lodging or other facilities are furnished, and for employees receiving remedial education.

Action by the Department
The Department is authorized to supervise the payment of unpaid minimum wages and/ or unpaid overtime compensation owed to any employee(s).  In lieu of litigation, the Department may seek back wages and liquidated damages, through settlements with employers. Liquidated damages can be as much as the back wages.  Civil money penalties may be assessed for child labor violations and for repeat and/or willful violations of FLSA minimum wage or overtime requirements.

Employers who willfully or repeatedly violate minimum wage or overtime pay requirements are subject to significant civil money penalties per violation.  Owners of a company can also be found to be personally liable.

Employers who violate the child labor provisions of the FLSA are subject to a civil money penalty of up to $11,000 for each employee who was the subject of a violation. These penalties may be increased up to $50,000 for each violation that caused the death or serious injury of an employee who is a minor, and may be doubled to $100,000 if the violation was determined to be willful or repeated.

All of this information was obtained form the US Department of Labor website.  Access to the specific site is http://www.dol.gov/whd/foremployers.htm. You are encouraged to contact the Department of Labor direct with any questions, comments or concerns.