I wanted to chime on and offer some observations on the progress of a case study I am working on in NYC.
The Facility has a 144,000 gallon Lap Swimming pool, Used primarily for Competitive Swimming and Training. It has HR Sand Filtration, A Cal Hypo HCF System, CO2/Acid pH Control, and an Aquionics UV System.
Initially, the Pool had chloramine issues in its air quality. Even with UV, the 6 hour Turnover, as we all know, was not allowing the UV light to see all of the water efficiently, to mitigate Chloramine Production, yielding high levels of Chloramine (Mono, Di, and Tri).
We did the Upgrades in the Fall of 2014, after one year of the pool's initial opening. The Chemtrac Controller was installed at opening, Featuring ORP/pH/Amperometric Free Chlorine (0-5ppm). We upgraded the Controller last year to also Measure Total Chlorine as well.
Upon the installations of the upgrades, we saw an immediate change in the air quality. No odors are present in the Natatorium Space.
Controller is maintaining:
Temp: 82 degrees F
Free Chlorine: 2.3ppm - 3.5 ppm, depending on demands.
Combined Chlorine based on Total Chlorine Sensor: 0-0.6ppm, depending on Demands. Further testing (Using a Palintest 25 Test Kit) shows that over 95% of the combined chlorine is in the Mono Chloramine Form, attributing to the lack of odor in the pool.
We will soon be turning off the UV system, and will be tracking the same levels to see if there are any changes.
Other Observations made:
ORP sensors last about 1 year under the Higher ORP levels. Tell Tale Sign: increased PPM level to about 4ppm to maintain the same ORP level, Once changed, the Free Chlorine Level Drops. Previous Studies indicated that PPM would go down as an ORP Sensor goes Bad...This is not the case.
I will now leave it for discussion...