|Wireless, Web Based CAT 4000 Automated pH/ORP Water
"ORP is the bottom line. Get it, somehow; it is necessary to make your water safe and to keep it safe."
Professional Pool Operators of America. www.ppoa.org
|The pool has not been closed once due to|
|100% safer, saved thousands of gallons of|
|water, and did not pollute the environment with |
excessive chemicals & by-products.
|The water chemistry has been checked and data|
|logged every minute, 24 hours a day, seven days a |
week, 365 days a year.
|We have made zero repairs on the controller.|
|(Routine maintenance & cleaning of the probes & |
chemical pumps only).
|Westside & Automated Water Chemistry
|Why Automated Controllers?
|Controller Concepts: ORP and Oxidation
A well-known study performed by Dr. Jim Brown of the
Oregon State Health Department about fifteen years ago
made it crystal clear that ORP is the qualitative measure of
choice for sanitarians or operators evaluating the safety of
pool variables plus plate count (bacteria density) and,
finally, ORP. Extremes showed up in pH from 5.7 through
8.3, combined chlorine from 1.4 to 34 ppm, free chlorine
from 0 to 30 ppm, cyanuric acid (what’s it doing in a spa??)
from 0 to 1,300 ppm, plate counts from 0 through 15,000,
and even Pseudomonas up to 12,400! The only correlation
that stood up throughout the study was the relationship
between ORP and the presence of pathogens. Virtually no
plate count existed in the spas where ORP values were
found to be above about 630 millivolts, while lower values,
no matter the free chlorine residuals present, all had
dangerous or near-dangerous levels of pathogenic life
Among the unsafe pools in the study, chlorine residuals bore
no resemblance to the plate-count values. Even when the
free chlorine was as high as 4 ppm, a significant plate count
existed because the ORP in that spa was 537 mV. The pH
was 6.9, so why was the ORP so low in that spa’s water?
Excessive cyanuric acid was the culprit, as was the case in
all but two of the thirteen spas exhibiting ORP levels at or
below 630 mV. No matter the reason for low ORP, however ?
low sanitizer, CYA, high pH, chloramines ? you could count
on unsafe water and eventual turbidity.
By Kent Williams ~ firstname.lastname@example.org
Executive Director and Editor
Professional Pool Operators of America
Conventional Swimming Pool Water
Testing & Treatment Provides
While many swimming pool operators and health officials
believe that a free chlorine residual of 1.5 to 3.0
parts-per-million provides sufficient sanitation, there are
several factors which have a significant impact on the
bactericidal effectiveness of the sanitizer. For example,
correcting the pH of a swimming pool or spa from 7.8 to
7.4 at a fixed free chlorine residual will cause a dramatic
reduction in the kill time for E. coli.
Most regulatory agencies set water quality requirements
based on the measurement of free chlorine residules with
DPD test kits. However, free chlorine is composed of two
distinct parts or species known as Hypochlorous acid
(HOCl) and Hypochlorite ion (OCl-), which are not equal in
their ability to sanitize. The ionic form of chlorine (OCl-) is
slow acting, while the Hypochlorus acid (HOCl) is 80 to
300 times more effective.
Unfortunately, bather loading and chemical dosing
constantly influence the dissociation between the two
chlorine species, rendering mandated sanitizer residual
levels and the DPD measurement thereof a weak tool in
maintaining bacteriological efficacy.
CAT Controllers www.chemauto.com
When it comes to maintaining healthy
pool water, ORP is actually more
important than ppm. What’s more, relying
on ppm readings alone can provide a
false, and dangerous, sense of security.
Decades of research have shown that ORP is a direct
measure of the sanitizer’s oxidation and disinfection strength
in the water. For instance, the polio virus dies in five minutes
at an ORP level of 550 millivolts (mV), but at a 650 mV ORP
level, it takes only 30 seconds to kill this virus. Add another
100 mV and the kill time is approaching one second! Kill
rates have been similarly established for all waterborne
pathogens along the ORP rate-of-disinfection scale — even
for cryptosporidium, E.coli, giardia and legionella.
By Jim Tanner, Siemens Water Technologies
May 2006 Jim Tanner is national sales manager of the
Aquatic Division at Stranco/Siemens Water Technologies.
His extensive aquatics background includes consultation and
17 years of designing and constructing aquatics facilities.
© 2006, Aquatics International
|Westside Pool CAT System
Installed on 50,000 Gallon Pool
|WSP CAT System
Installed on Spa