Over the course of the last several decades, onBalance has released research data showing the effects on swimming pool plaster from many variables. This data was generated from field observations, failure analysis, laboratory experiments and forensic petrographic analysis. Failures investigated have included a wide range of plaster defects and plaster deterioration, including but not limited to calcium nodules, delamination, mottling, spotting, drip lines, etching, leaching and scaling (calcite depositing), organic vs. inorganic pigments, filling a pool too soon after plastering, excess chloride, and more. Petrographers have been able to determine the cause(s) of failures using techniques ranging from scanning electron microscopy (SEM), x-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and stereo microscopy to chemical analysis of the plaster.

Research of cement/concrete industry literature has shown that the results of these petrographic analyses are corroborated by cement/concrete industry data, where similar materials, workmanship, and environmental variables have had similar effects in various types of mass concrete.

The findings have also been consistent with our wide-ranging field experience, each of the onBalance partners having three to four decades of hands-on experience in maintaining thousands of residential swimming pools.

In order to further support these findings, and to illustrate the relationships found by our experience and by the literature and petrographers in a demonstration pool setting, onBalance will be building two demonstration pools in the Tucson, Arizona area.

Areas of Investigation, Series One:

– The Effect of Varying Levels of Calcium Chloride on White Cement Plaster

– The Effects of Aggressive vs. Balanced Chemistry on the White Calcium Chloride Plasters

– The Effect of Constant Low-level Chlorination vs. Periodic Superchlorination Chemistry on Various Organic and Inorganic Blue and Black Pigments

The test facility will be composed of two pools, each 12 by 8 feet with a 3 foot constant water depth, and an overall height of 3.5 feet. Each pool will be plastered in four sections, with tile lines dividing each section. These sections will run along the eight foot width of the pools. After plastering is complete, a PVC divider will be inserted across the 12 foot length of the pool, dividing the pool in half. This allows for each plaster section to be subjected to different water conditions on each side of the divider. Each demonstration pool will have two filtration systems, one for each side of the divider.

Pool 1 will observe the effect of varying levels of calcium chloride on white plaster, as well as the effects of aggressive versus balanced chemistry on said plaster. The plaster sections will contain 0, 1, 2, and 3% calcium chloride. Then, after subdividing the pool, each level of calcium chloride will be subjected to either balanced or aggressive water.

Pool 2 will observe the effect of constant low-level chlorinated and periodically superchlorinated water conditions on blue and black, organically- and inorganically-pigmented plasters. The water on both sides of this pool will be maintained in an LSI balanced condition.

Over the course of the year, the surfaces will be regularly evaluated at poolside by visual and tactile examination for the following: Aesthetic Appearance, Texture (smoothness vs. roughness), Comparative Color, Consistency of color, Mottling, Spalling, Spotting, Streaking, and Crazing. Core samples will be removed periodically from the various plaster sections and submitted to a petrographer for evaluation, including Chloride content, Porosity, Leaching, Etching, Calcium deposition, and Color.

Funding for this project is being provided by donations from various manufacturers, distributors, service companies and trade association groups. These include the IPSSA Region 7 Tabletop ($10,000 in matching funds), the Tucson IPSSA Chapter, Meadows Pool Plastering, Mortex (Kool Deck), Universal Cement, Hayward, and various individual service companies, including Aqua Clear and Pool Chlor.

The results will be provided to the industry on a regular basis throughout the course of the demonstration, at no charge. If you are interested in participating in this project, by donation of materials, labor, funds, etc., please contact onBalance. We appreciate all of the industry support.

Lab and facility address: 3114 E Pennsylvania St., Tucson AZ 85714 – 520–573–6696