Homeowners should take great care when deciding to (or not to) acid wash a pool.
The idea of acid washing may seem like a good idea. Removing rust, removing stains, recreating that brilliant look of a new surface. What's not to like? But consider the process that is occurring to your pool/spa surface BEFORE you act.
Before anything else, first consider the outside daytime temperature. I prefer to acid wash when the high temp is 75 degrees Fahrenheit or lower, especially with plaster ( white cement ) pools. If you take on a project like this with warmer weather, be mindful of the heat affecting the surface. Blistering/cracking may occur if you don't.
What does the acid solution actually do? It eats and etches part of your cement.
That's how you get the fresh, new look. It removes some of the surface, exposing the surface underneath. When your surface is new, its smooth, more or less. Providing an excellent surface for the dirt and debris to slide along down to that bottom drain to be gobbled up. After acid washing has been done it is likely that some roughing may have occurred. That said, it's more difficult for the earlier mentioned debris to slide well (it's like going down a pool slide without water, ouch!).
If the pool gets rough, it can also create an environment for different types of algae to hide and develop, even with proper brushing. We could also consider nodule development being a possible result, but I'll save that for another discussion.
I have done hundreds of acid washes during my 14 years as a pool professional. My techniques are careful, my process is sound, but sometimes I find that refusing to do an acid wash is a better solution for the longevity of a cement pool or spa.
Alternatively, consider a stain removal chemical. There are many on the retail market.
About the
author:
Since 1999, Rick
DeRouin has worked closely with manufacturers and
veterans of the swimming pool industry, learning proper techniques
and honing his craft. His goal is to bring you the most accurate
information and treatment methods possible for your pool/spa needs.
Rick has hundreds of hours of classroom experience and many, many
years of field experience.
Rick's Pool Care LLC