The great evolution in recreational aquatics began in the mid- to late-1970s, when water slides began popping up everywhere that a Florida contractor could pile up a sand hill. Developers were so concerned about building good slides that they paid little attention to matters such as water treatment. Many simply installed a residential-sized filter and let it fly at three turnovers a day.
Wave pools arrived on the scene at about the same time. Some of you may even remember wave pools with side gutters and skimmers â€” neither accomplished anything, it turned out. And not that long ago, lazy rivers had skimmers every 25 feet.
Today, most lazy rivers have a single, large skimmer for approximately every 1,200 feet of length.
Sometime in the early 1980s, operators began to wonder why the wave pool water turned cloudy each afternoon. Some blamed the filtration system; others claimed it was poor chemical treatment. Both were right.
At many facilities, chemical feed pumps ran at full tilt, but no chlorine materialized in the water. Simultaneously, pH readings were off the chart â€” on both ends of the scale. More and more, we heard about unexplained chemical overdosing. What was going on?
Water park operators began to realize that equipment specifications for traditional pools don’t cut it for water park attractions. For example, chemical feeders for traditional pools generally have maximum outputs of 1/2 to 1 pound of chlorine equivalent per 1,000 gallons per day. At heavily loaded wave pools, though, chemical feeders often must pump 2 or 3 pounds per 1,000 gallons per day.
While feeders usually run at this high rate for just a couple of hours each day, without this ability, chlorine levels could plummet to zero during peak hours and the water would turn cloudy almost immediately. It’s common to find a wave pool chlorine feeder chugging along during peak hours at a rate of 1,200 to 1,500 pounds of chlorine or gallons of bleach per day.
During off hours, some operators have found it necessary to set feed rates to lower levels (as low as 100 pounds of chlorine or gallons of bleach per day on wave pools) to prevent high chlorine spikes during periods of low use. Undersizing the chemical feeder systems during new installations is a common design mistake. When sizing new systems, it’s always better to err on the high side.
General guidelines for pool chemical feeders:
- Wave pools: Peak capacity of 2 gallons of sanitizer per 1,000 gallons of water.
- Lazy rivers: Peak capacity of 1.5 gallons of sanitizer per 1,000 gallons of water.
- Catch pools: Peak capacity of 3/4 to 1 gallon of sanitizer per 1,000 gallons of water.
- Low-water-volume attractions (such as racing hills and interactive play systems): 1 to 2 gallons of sanitizer per 1,000 gallons of water during operation. Overnight, operators should run as little as 1/4 gallon per 1,000 gallons to keep the system from overpowering the pool.
Remember, sanitizer feeding is a guessing game â€” one size does not fit all. The smart approach is to constantly check the sanitizer levels, be ready to adjust on the fly and to ensure that your hardware is big enough to meet peak demands.
If you have unanswered questions about water park operation, we have consultants that will be happy to help.