Trichlor and automation
This is a letter your editor wrote, about 8 years ago,
to a contractor about his interest in using a tri-chlor
erosion feeder to treat a busy, automated public pool.
The study referenced in the last paragraph is on line here
in Tech Articles, called Cyanurics, Benefactor or Bomb.
In the letter below I had to blow my horn a bit in the
first paragraph to make sure he knew I meant business and
had the background. Feel free to skip to paragraph 2…
Dear Sir,
At your request, I am responding with information and opinion
regarding cyanuric acid's devastating effects on ORP instrumentation,
specifically regarding trichloroisocyanurates used in the
public-pool setting. I feel qualified to offer this opinion
as I am a long-time institutional swimming-pool consultant
focusing on operator training, renovations, chemical analysis
and automation. I am a graduate electrical engineer, having
served the pool industry as a systems and automation designer
and water-treatment-system consultant for twenty five years.
I have been on committees for code writing and approval in
California, Texas, Nevada, Oregon and elsewhere, and served
on the NSPI/American National Standards Institute Pool-Code-Writing
Committee working on the new U.S. code. I am founder and
executive director of the Professional Pool Operators of
America. I wrote the textbook and the curriculum for the
National Recreation and Parks Association's Aquatic Facility
Operator training course. My specialty remains pool-water
treatment.
First, let me say that the choice of "Tri-chlor" as
a sanitizer is wholly inappropriate for any public swimming
pool. The accumulation of cyanuric acid becomes debilitating
to the oxidation/reduction potential (ORP) necessary for
maintenance of water clarity and, ultimately, sanitation.
As all swimming-pool automation devices measure the qualitative resultant
of the presence of chlorine or bromine residuals, NOT the
quantitative (parts-per-million) values read by test kits,
the detracting effect of accumulating cyanuric acid has consequential,
unacceptably depressing results on the ORP.
The Strantrol System 5 controller is among the best, most
consistent and reliable in the industry. One of these systems
could, in fact, function adequately in the presence of cyanuric
acid; however the variable and rising residuals make constant
attention and calibration required. An untrained operator
would have little chance of making any brand of controller
function satisfactorily under such conditions. The machine
feeds enough sanitizer to achieve a chosen and necessary
ORP; it may take very high residuals to do so in the presence
of CYA!
I have included a study, presented to the National Symposium
of Pool Water Chemistry in Los Angeles, 1998, which supports
the critical argument against CYA in the high-load public
environment. Please read this work and pass it on as necessary.
I hope you have acquired an Aquatic Facility Operator manual,
in which you will find a summary of this information in Chaper
13.
I hope this helps.
Kent G Williams, Aquatic Consultant
Executive Director, Professional Pool Operators of America
~
kw
© 2007
Professional Pool Operators of America
