acid column

2013/5.2, May 22 — Cantilevered Beauty, Dispelling a Water-Treatment Myth, Chicago’s Signature Fountain and more
                             May 22, 2013        …
Exploring the ‘Acid Column’
When I conduct seminars at pool and spa industry trade shows, I regularly get asked about the validity of a water-management technique known widely as the “acid column” approach. Those who believe in this application method say that if acid is poured into a swimming pool in a concentrated area – producing what adherents variously call a column, slug, well or cloud – the alkalinity of the water will be drastically reduced, but the pH will not drop as much as it otherwise would.  By contrast, they say, if that same volume of acid is added by walking it around a pool and evenly distributing it throughout the water, the pH will be