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Here is what appears in Volume 3 Number 2 of the Journal of the Swimming
Pool and Spa Industry:
General:
An Introduction to the Journal
Articles:
Kim Skinner and J. Que Hales
Pool Chlor
Doug Latta
Aqua Clear
New Plaster Start–up Chemistry Using Sodium Bicarbonate
A study was performed that compared the effects of different chemical
start–up procedures on the surface of swimming pool plaster. Lab research
was performed by simulating traditional start–ups and acid start–ups
(both utilizing muriatic acid), and high alkalinity start–ups (using
sodium bicarbonate) with plaster coupons, which were subsequently analyzed.
Field research was also conducted to confirm consistency with the lab results.
Experimental results and conclusions are given.
Kim Skinner and J. Que Hales
Pool Chlor
Calcium Nodules
A study was performed that examined the chemical basis behind the formation
of calcium nodules on swimming pool and spa plaster. A chemical model was
developed which was consistent with both the chemical rationale and with
actual nodule samples collected from swimming pools. A laboratory study
was designed and successfully conducted to artificially “grow”
nodules on plaster coupons.
Richard Dietz
Aqua Creations
The Viability of Fiberglass as a Pool Surface Alternative
The installation of fiberglass liners in swimming pools has been used
with varying degrees of success for approximately 25 years. This paper will
discuss the viability of fiberglass as a low maintenance alternative to
traditional plaster surfaces, and discuss specific problems resulting from
the application and maintenance of the product, along with strategies to
avoid these problems..
John A. Wojtowicz
Chemcon
Swimming Pool Water Buffer Chemistry
Buffering is the resistance of water to pH change. Water itself has
little buffering in the 5 to 9 pH range. Therefore, buffering agents are
necessary to prevent severe pH fluctuations that would otherwise occur when
acidic or basic sanitizers are added to pool water. The presence of alkalinity
in the form of bicarbonate and cyanurate imparts buffering to swimming pool
water. A buffer system consists of a weak acid and its anion (e.g., carbonic
acid and bicarbonate or cyanuric acid and cyanurate). A buffer system resists
pH changes in either direction because it can react with either acidic or
basic substances that are added to swimming pool water. However, because
of the relatively low concentrations of buffering alkalinity carbonate,
cyanurate, or borate) in swimming pool water, the acid or base neutralizing
capacity without significant pH change is limited. Although the buffers
in swimming pools can neutralize minor quantities of acidic or basic substances
with only small pH changes, significant pH changes will occur if large quantities
of sanitizers (especially acidic) are added or if acid is added, eg, during
pH adjustment. Maximum buffering occurs at a pH where the molar ratio of
acid to anion is one. At 80°F and 1000 ppm TDS maximum buffering occurs
at pH 6.3 and 6.8 for the carbonic acid/bicarbonate and cyanuric acid/cyanurate
systems, respectively. By contrast, maximum buffering in the boric acid/borate
system occurs at pH 9.2. On a molar basis, the cyanuric acid/cyanurate system
provides more effective swimming pool water buffering at pH 7.5, 80°F,
and 1000 ppm TDS because its pH of maximum buffering is closer to pool pH.
However, on a ppm basis, the buffer intensity of the carbonic acid/bicarbonate
and cyanuric acid/cyanurate systems are roughly comparable over the recommended
pH range (7.2-7.8) and greater than that of borate at pH less than 7.8.
At pH 7.8, the buffering of the three systems are roughly comparable on
a ppm basis. At and above pH 7.8, borate significantly supplements swimming
pool buffering.
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