Science-Based Swimming Pool Maintenance

There are about 20 million swimming pools on earth, maintained at an average cost of more than $500 per annum for chemical inputs, plus the costs of electricity for pumping and heating. Pool maintenance is a multi-billion dollar industry internationally.

The number of pools, their combined operating cost, and their environmental footprint increase with average living standards. Most pools are now domestic, and managed by their owners with varying degrees of technical input from the manufacturers and retailers of pool supplies, pool service providers, and user forums. Advice from these sources is often conflicting. Therefore, a compelling case exists on financial and environmental grounds for far greater scientific input -- through research, critical analysis and dissemination of knowledge -- to support science-based decision making in swimming-pool management.

The objective of this part of the site is to provide critical reviews of the science behind the practical art of effective swimming pool maintenance. You are welcome to download any of these files. Please feel free to use the material however it helps. Just reference the source article if you wish to reproduce any part of the content.

Boric acid as a swimming pool buffer

Summary: Boric acid in equilibrium with its conjugate base, the borate ion, has been applied increasingly in recent decades as a pH buffer system in swimming pools. This article provides a critical review of chemical and biological factors relevant to this application, based primarily on the refereed scientific literature. It examines basic chemistry, sources and conversion factors, safety and toxicology, pH buffering, and potential side-benefits including antimicrobial activity, anti-corrosive properties, photostabilisation of hypochlorite, and sensory effects such as water softening and colour. By highlighting some advantages of borate over bicarbonate as a buffer in salt-water pools, defining safety precautions in terms relevant to pool use, and noting the limits to scientific understanding of some potential side-benefits; the review should assist in science-based decision making about adoption of boric acid as a primary or adjunct buffer in swimming pools.

Reference & Link: Birch RG (2013) Boric acid as a swimming pool buffer. https://scithings.id.au/Boric_acid.pdf

BABES: a better method than “BBB” for pools with a salt-water chlorine generator

Summary: A swimming pool is an aqueous solution of interacting chemicals that determine appeal and safety for swimmers. The chemistry varies widely, depending on what is added to the pool. In recent decades, there has been an increasing trend towards domestic outdoor pools that use electrolytic salt-water chlorine generators for sanitation (SWC pools). These typically have cyanuric acid for photoprotection, and sometimes boric acid for improved pH buffering. Critical thinking about the chemistry indicates simple principles for efficient SWC pool maintenance, some of which differ from the traditional advice to non-salt pool operators. This article describes a simple approach built on the “BBB” tradition. The improved “BABES” method integrates the use of boric acid for pH buffering, hydrochloric (muriatic) acid to correct pH updrift from SWC operation, brushing to help prevent biofilms, electricity and common salt for sanitizer production. It explains the contribution of each of these components, then explores the scientific basis for the few additional compounds that should be considered, and those that should be avoided, for trouble-free SWC pool maintenance. Along the way it points out key myths and uncertainties to encourage deeper analysis. It ends with a simple set of operational guidelines that an SWC pool operator can confidently adopt, or vary to suit their needs based on the scientific foundations in the article.

Reference & Link: Birch RG (2013) BABES: a better method than “BBB” for pools with a salt-water chlorine generator. https://scithings.id.au/BABES.pdf

What if the pool gets flooded?

Summary: A swimming pool that gets flooded by surface runoff or riverine flooding can look very muddy and seem like a nightmare for an owner experiencing this rare event for the first time. But it is not as much trouble as it looks. With some manual work and the right pool chemicals, a muddy pool can be restored to a safe and appealing condition for swimming within a week. This short article gives practical advice on recovering from flooding of an outdoor salt-chlorinated swimming pool.

Reference & Link: Birch RG (2023) What if the pool gets flooded? https://scithings.id.au/Flooding.pdf

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Any input or corrections supported by reference to a peer-reviewed scientific publication will be considered for revision of the reviews above.