
The latest research concerning cyanuric acid has clearly stirred conversation within the industry.
Last fall during trade show and convention season, animated debates took place about a recommendation by an ad hoc committee for the Council for the Model Aquatic Health Code to limit CYA to 20 times the levels of available chlorine in commercial pools and spas. On the residential side, research and recommendations from pool/spa chemistry beacon Robert Lowry have some service technicians trying new things.
Here, a look at some of the reactions and impact from the research, which was discussed in a previous article (“A New Phase for CYA,” Oct. 7 2019).
Opposing View
Reception to CMAHC’s paper has varied across the spectrum.
There are those who believe that the work, and the entire subject, amounts to much ado about nothing. Perhaps the most vocal critics of the paper come from manufacturer BioLab. Various officials with the producer of chlorinated isocyanurates point to the fact that no RWI incidents have been documented in pools with chlorine levels falling between the 1-4 ppm mandated in various codes and standards. The one exception is cryptosporidium, which has proven resistant to chlorine.
Rather than focusing on CYA levels, the manufacturer believes the industry should find ways to ensure that technicians and operators follow the standards and guidelines already available.
“We’ve got close to 12% of swimming pools that are closed instantly during an inspection because they are not properly disinfected or the pH is [off] or the pump isn’t running,” says Roy Vore, technology manager for BioLab. “We’ve got outbreaks that are easily controlled by chlorine today, when we’ve got operators who are not following standard practices.”
The company has taken issue not only with the need for the CMAHC’s study, but also some of the methodology.
For instance, as reported in the first installment, part of the CMAHC committee’s report focused on how sanitizer levels affect the removal of giardia. Vore believes other pathogens deserved first consideration.
“We have people getting sick from pseudomonas and legionella, which are easily killed by 1 ppm of free chlorine,” he says. “We need to focus on the critical organisms and straighten out what’s going on now before we tinker around with a 40-year-old management practice.”
Holding out for more info
Others either aren’t concerned or have taken a wait-and-see stance.
“I think the majority of people arguing about it are the scientists,” said Joe Laurino, chairman of PHTA’s Recreational Water Quality Committee (RWQC). “I think the majority of people are thinking, ‘We know it has an impact but until we know what to do we’re not going to focus on a [ratio].’”
The CMAHC paper did get the RWQC’S attention. At the World Aquatic Health Conference in October, the committee discussed the CMAHC paper and what impact, if any, it should have on PHTA’s commercial water quality standard, currently called the ANSI/APSP/ICC-11 Standard for Water Quality in Public Pools and Spas. (In future editions, the name will change, with APSP replaced by PHTA.)
But ultimately it appears members aren’t motivated to propose changes to PHTA-11’s CYA limits as it prepares to begin the next revision cycle. After discussing the CMAHC paper, Laurino suspects that not enough of its members would be swayed to vote for a change to the current language, which sets a maximum CYA level of 100 ppm and a minimum chlorine level of 1 ppm (2ppm with more than 50 ppm of CYA). The group, he believes, is comfortable with the range of de-facto ratios imposed by the current language.
“I don’t see there being significant literature for us to change that at this point in time,” he says. “Based on the latest scientific information that’s been published, I don’t think there’s enough information from peer-reviewed articles or data that would support changing that number.”
Additionally, he and others believe that evolution will solve some of the CYA issues. From a pathogen-management standpoint, Laurino had already planned to suggest that the next version of PHTA-11 be revised to require secondary disinfection on all commercial pools, spas and waterfeatures. Currently, the standard calls for this measure on high-risk water elements such as spray pads, which must have secondary disinfection systems capable of 3-log reductions. His proposal would suggest adding systems capable of 1-log reductions, which are significantly less expensive, on non-high-risk venues.
While the CYA question wasn’t the initial motivator for this move, it could have a beneficial ramification, Laurino says. These systems have a track record of killing crypto, which is chlorine-resistant and the most difficult pathogen to eliminate. So if a technology can rid crypto, it likely will remove everything else. This would serve as a backup and remove the pressure of compensating for any drops in chlorine efficacy, he and others believe.
But product innovation should also help address one of the everyday-practicality issues that comes with CYA — namely the need to perform dilutions to test water with very high CYA levels. New higher-end test kits have begun entering the market that can accommodate CYA levels up to 300 ppm, well above current standards.
The Residential Perspective
Residential service technicians, in particular, don’t feel a sense of urgency from the CMAHC paper.
They don’t worry about RWIs since bather loads are so low in the pools they maintain. They mostly want to know about practical issues, such as how to test water with high CYA levels.
So they are waiting to see what new findings CMAHC’s work yields before changing their practices. However, some techs have responded to Bob Lowry’s new system, which was discussed in the previous article and recommends free chlorine levels of at least 7.5% of CYA readings.
David Hawes, president of IPSSA and CEO of H&H Pool Services, in Dublin, Calif., is one such person. While he doesn’t feel strongly one way or the other, he decided to change his regimen to achieve lower CYA levels. Rather than maintaining levels of 80-100 ppm, his company now aims for 30-50 ppm.
To do this, the team altered the recipe it uses on its pools each visit — for them, a combination of tablets and liquid chlorine — to include higher amounts of liquid and fewer tablets. He basically wanted to see how it worked out.
“[All the research] made sense on paper, but you know what I say? Everything looks good on paper. So we just decided to try it,” Hawes says.
After two seasons, the company has seen no problems from the CYA reduction. Generally speaking, the pools have been less problematic — but other changes that his company made to its regimen also may have contributed, so he’s not ready to say the CYA reduction is the cause. But the results have been encouraging enough that Hawes may make it a policy for his technicians to aim for 30 ppm CYA, rather than the broader range of 30-50 ppm.
Industry chemistry expert Terry Arko also has heard success stories about applying the 7.5% rule in the backyard to prevent algae and other problems.
“I know that people have had a lot of success using that ratio, where problems existed before,” says the product training consultant with chemical manufacturer Hasa. “I’m talking to service technicians, and I’ve been hearing that it seems to be working.”
Looking to the field
With the conflicting studies and opinions, some are calling for research and data gathering to be performed in the field to help clarify it.
As Arko sees it, so much of the information coming out recently has been on an academic level. And the loudest voices have come from the larger sanitizer manufacturers who have the most at stake, so he sees a bit of an impasse there.
“I think the information that’s coming out is good, and it’s timely. The industry has needed it,” he says. “But I feel like we need to hear from the pool techs also, because they’re the ones out there doing it day in and day out. What’s going on in their water? What are they experiencing? I think that’s what’s missing right now in the discussion.”
Laurino believes some controlled testing would also be appropriate to put the existing research and CMAHC’s model to the test in a real-world environment.
“Because it’s a model and the model predicts, one has to look at the variability within that model,” he says. “I would need to see that model being tested in real life. Does the model work in the real world? They need to test their assumptions [on which the model is based].”
What’s next
As for the CMAHC study and its potential impact on the Model Aquatic Health Code, we won’t know that for sure until early 2021, when the next edition is finalized.
The CMAHC ad hoc committee that wrote the paper will likely translate the paper’s recommendations and findings into multiple change proposals, to separate the more controversial or less solid recommendations and help the more definitive ones gain approval.
For instance, the 20:1 ratio that the paper proposes will appear on its own change proposal, since some in the committee believe the need for a chlorine-CYA ratio stands on more solid ground than the actual number proposed.
The CYA conversation has gone on for decades, and it appears likely to continue for years to come.