It was a brand-new indoor facility, and running a pool untouched by age, corrosion or out-of-date construction standards seemed like a dream come true. But it soon turned into a nightmare.

Halfway through our first two-hour swim team practice, members began coughing due to high free chlorine levels. We hadn?t had a chance to balance everything yet, and were still getting the hang of the new chemical controllers, which used ORP readings. So we were surprised the next night when the same problem occurred. Parents started complaining and, after two such practices, the team left for another pool.

The first issue we discovered: Our air-handling system was set on a schedule, but nothing had been programmed. Instead of bringing in fresh outside air, pool air was being recirculated. We quickly fixed the problem, and the team came back.

When the issue resurfaced, we decided to forego the money-saving ?schedule? feature and run the air handler 24/7. No more complaints were registered for three weeks, and we thought we had solved the problem until the team began practicing twice a day.

We had the chemical levels tested by an outside party. Our monthly health inspection came back fine. So we began running our air-handling system on ?purge? cycles during swim team practices, which brought in periods of 100 percent outside air. Still, issues persisted with the swim team only.

We were baffled. Our chemical readings were within acceptable ranges. The combined chlorine levels stayed somewhere between 0.4 to 0.6. We began super- chlorinating the pool every weekend, and treating it with nonchlorine shock after practices. Regardless of what we did, the combined chlorine levels never budged.

We had to move the team to another pool while we worked to resolve the problem.

We scheduled a meeting with the air-handling, filtration system and chemical control manufacturer representatives. Recommendations were taken; accusations were thrown. The air-handler reps insisted the product was built ?to code.? But did ?code? include the possibility of high-volume, high-intensity usage? Everyone affiliated with the chemicals insisted that a combined reading of 0.5 was not dangerous, and that while 0.0 was ideal, it was nearly impossible to maintain.

In the end, we increased air handler capacity to accommodate a larger bather load, going above and beyond the ?to code? standards. We conducted tests using dry ice to determine airflow around the natatorium, then redirected some vents to more thoroughly move fresh air across the pool. Lastly, we began looking into ultraviolet light system.

Two days after installing the system, our previously indestructible combined chlorine level was 0.0. Three months later, the team hesitantly came back. After a month, we had no complaints from any team members.

Now our combined chlorine readings never venture above 0.2 and hardly ever get to that level. After months of experimentation and frustration, the problem is solved, though it will be much longer before the negative image of the facility is erased from the community?s memory.