Membership Directory & Resource Guide - 2018 - 24

TECHNICAL BULLETIN NO. 3 * 2016 * pg 4 of 4

range of -0.3 to +0.5, they state the ideal range
to calculate the Saturation Index. Also, with higher
is
0.0
to
+0.5.
The
NPC
further
refines
the
ideal
salt levels,
the water can be more aggressive.
Swimming Pool Interior Finishes & Chemical Etching
Deterioration
Issue No. 3 / PG 5 of 5
range to 0.0 to +0.3. Certain high performance
Conclusion
durability finishes can tolerate slightly negative
indices
for chemical
short periods
of time. in direct contact with interior
Some
compounds
finishes
cause
dissolution
or
Swimming
pool can
interior
finishes
are designed
to

alteration of these pool surfaces. Compounds suchprovide
as cyanuric
acid (stabilizer)
and salt (NaCl)
can
a serviceable
and aesthetically
appealing
Some
chemical
compounds
in
direct
contact
create conditions that will have significant impact on
thetoSaturation
Index calculations.
finish
the pool. Therefore,
to prevent For
etching
withexample,
interior finishes
cancyanuric
cause dissolution
elevated
acid levelsor(CYA) will impact
the carbonate
alkalinity
measurement.
deterioration
along with
other issues,
the most
alteration of these pool surfaces. Compounds such
critical
care to
item
is maintaining
proper water
Remember, only carbonate or adjusted alkalinity can
be used
calculate
the Saturation
Index.
as cyanuric acid (stabilizer) and salt (NaCl) can
balance.
To
optimize
the
long
term
durability
and
Also, with higher salt levels, the water can be more aggressive.
create conditions that will have significant impact
appearance of any cementitious interior pool finish,
on the
Saturation Index calculations. For example,
Conclusion
proper materials, proper workmanship and balanced
elevated cyanuric acid levels (CYA) will impact the
water chemistry
mustand
all be
present. appealing
Swimming
poolmeasurement.
interior finishes
are designed to provide
a serviceable
aesthetically
carbonate
alkalinity
Remember,
to theorpool.
Therefore,
prevent
etching deterioration along with other issues, the most
onlyfinish
carbonate
adjusted
alkalinitytocan
be used
critical care item is maintaining proper water balance. To optimize the long term durability and
appearance of any cementitious interior pool finish, proper materials, proper workmanship and
balanced water chemistry must all be present.

References:
1.
2.
3.
4.
5.
6.
7.
8.

Other General References:

The Association of Pool and Spa Professionals, "Service Tech Manual", 4th Edition, V. 4.3,
Alexandria, VA, 2013.

NPC MEMBERSHIP DIRECTORY & RESOURCE GUIDE

Technical Bulletins

National Plasterers Council, "Technical Manual", 8th Edition, 2016, pgs. 5 - 8.
Steven H. Kosmatka, Michelle L. Wilson, "Design and Control of Concrete Mixes", 15th Edition, 2013,
Portland Cement Association, Skokie, IL, pg. 49.
Adam Neville, "In My Judgement - There is More to Concrete than Cement", Concrete International
Magazine, January, 2013, pgs. 73 - 74.
Sidney Diamond, "Cement Paste Microstructure in Concrete - Microstructural Development Driving
Hydration of Cements", Materials Research Society, Symposia Proceedings, Vol. 85, pgs. 21 - 31.
National Plasterers Council, "Technical Manual", 8th Edition, 2016, page 25.
ANSI/APSP - 11, "American National Standards for Water Quality for Public Pools and Spas", Appendix A,
Sections A-1 to A-3, 2009.
National Plasterers Council, "Technical Manual", 8th Edition, 2016, pgs. 25 - 26.
ANSI/APSP - 5, "American National Standard for Residential Inground Swimming Pools", Appendix A,
Sections A-1 to A-3, 2011.
National Plasterers Council, "Technical Manual", 8th Edition, 2016, pg. 27.

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