Executive Summary
On May 3, 1992, the Florida Solar Energy Center (FSEC) began an eight-week evaluation of a solar-powered pool purification device designed and manufactured by the Floatron Corporation. The evaluation concluded on June 28, 1992.
The Floatron unit uses a small photovoltaic panel to supply electricity to two electrodes. These electrodes produce copper and other ions that inhibit the growth of microorganisms. The device floats in the pool and works when exposed to sunlight.
During the testing period, daily water samples were analyzed for pH, alkalinity, cyanuric acid, calcium hardness, total and free chlorine, copper ions, and temperature. An Olympus microscope was used to check for algae and bacteria. Pool walls were visually inspected each day.
The evaluation was conducted in three stages:
1. Standard pool operation with chlorine
2. Floatron operating while chlorine levels dropped to zero
3. No chlorine or Floatron in the pool
The device was also tested in FSEC’s photovoltaic labs.
Key Findings:
• The Floatron reduced the need for chemical treatments while keeping the pool free of algae and bacteria.
• Measurable copper ions appeared after one week, reaching the effective purification level of 0.2 ppm after eleven days.
• The unit maintained clear water for over a week without chlorine, though best results occurred with a trace chlorine level of 0.5 ppm (about 25% of typical recommendations).
• A persistent yellow algae issue on the pool’s east wall was eliminated.
• Ion levels remained stable for over a week after removing the device and were still measurable three weeks later.
• Pool clarity didn’t decline until three weeks after chlorine hit zero, partly due to over four inches of rain in three days.
Electrical Performance:
• The unit produced 1.53 watts under full sunlight.
• Based on the panel’s polycrystalline structure, it should operate effectively for at least ten years.
Additional Note:
The lead investigator has personally used a Floatron in his pool for over a year, floating it every other week and using less than 13 gallons of chlorine annually, with minimal issues.
1. Introduction
There are over three million in-ground swimming pools in the United States, according to the Swimming Pool Manufacturers Association. The National Pool and Spa Institute estimated that as of July 1991, Florida alone had over 530,000 of these pools. Chlorine and other sanitising chemicals are commonly used to maintain water quality in most of them.
In the late 1960s and early 1970s, NASA researched alternative methods of water purification for astronauts. Copper and silver ionisation was found to effectively prevent algae and bacteria growth.
Like many space innovations, this technology eventually made its way to consumers. The Floatron Corporation combined ionisation with photovoltaic cells to create a self-contained pool purification device. FSEC was approached to evaluate the Floatron in a typical Florida pool. This report documents that test and includes the principal investigator’s year-long personal experience using the device.
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2. Experimental Approach, Methodology, and Test Results
A three-phase test was conducted using a 17,000-gallon, unscreened marcite pool on Merritt Island, Florida. The pool receives full sun during the day, except in the early morning.
Chlorination was managed via an inline automatic chlorinator using 3-inch chlorine tablets. The owner typically used three tablets per week in summer and one per week in winter, along with about one gallon of algicide monthly to combat yellow algae. The pump ran for eight hours daily.
Phase One:
For one week, the pool was monitored using the owner’s standard chemical routine. Brushing occurred twice a week, and vacuuming once. Water was tested daily using a Taylor K-2005 kit, with chlorine kept at 8.0 ppm and calcium hardness over 600 ppm. Chlorine costs from past receipts were over $300 per year.
Phase Two:
The Floatron device was placed in the pool and tethered near the skimmer. Daily testing included copper ions using a Taylor K-1730 kit. Copper ions reached 0.05 ppm after 7 days and the recommended 0.20 ppm after 11 days. Chlorine levels dropped to zero after about a month. Calcium hardness dropped from 800 ppm to 500 ppm. All other levels stayed normal. No algae or bacteria were detected.
Phase Three:
Floatron was removed, and no chlorine was added. Copper ion levels remained within the recommended range (0.20–0.40 ppm) for 25 days. No algae or bacteria were seen, and the pool stayed clear despite warm temperatures (average 82.7°F). The test ended after three days of heavy rain degraded pool clarity. Cyanuric acid dropped slightly. All other levels remained stable.
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3. Long-Term Experience
As of July 30, 1992, the lead investigator had used a Floatron in his own 12,000-gallon, unscreened Cocoa Beach pool for over a year.
Before using Floatron, the pool required around 10 gallons of liquid chlorine weekly during summer, half that in winter, and 0.5 gallons of muriatic acid weekly. Despite regular maintenance and algicide use, black algae was a persistent issue.
After installation, copper ion levels reached 0.2 ppm in two weeks. With experience, floating the unit every other week proved sufficient to maintain levels without constant monitoring.
Chlorine usage dropped to about one quart per week—enough to maintain clarity through oxidation. During a one-month absence, the Floatron alone kept the pool algae-free. After a clean and minor chlorine dose, the water was crystal clear again.
Since adopting the Floatron, the user has had no algae issues. Maintenance time and chemical use dropped significantly, and the device has operated flawlessly.
4. Summary of Results
The following conclusions can be drawn from our evaluation:
The floatron device is very effective at eliminating algae. The test pool required a once a month introduction of algicide to stop growth on the east wall prior to the ntroduction of the device. Within ten days of
the Introduction of the floatron device to the pool the algae was eliminated and did not recur during the test period.
The floatron device begins producing ions immediately after being placed in a pool when exposed to sunlight, and will produce ion levels sufficient for pool purification within two weeks (depending on pool volume) provided insolation levels are sufficient.
The floatron device greatly reduces the need for chlorine. Based on the results of the test, it appears that the test pool will operate with between 75-85% less chlorine, depending on bather load, when the copper ion level is maintained within the manufacturer's recommended range.
The Ion levels produced by the device drop fairly slowly. In the test pool, it took over three weeks for the level to drop from the top of the recommended level (0.40 ppm) to the bottom recommended level (0.20 ppm).
The electrical performance of the unit is sufficient to produce ions under various solar conditions.
The floatron device reduces calcium hardness levels and water hardness levels by precipitating these metals onto the coil electrode. The device lowered the calcium hardness level in the pool by 100 ppm during the test period.
In summary, based on our test results and year of experience we find that the floatron device is an effective way to reduce chemical use and eliminate algae while maintaining superior water chemistry.