What is an acid wash and how is it done?
An acid wash is a procedure done on a plaster or pebble tec pool to remove a very thin layer of the surface in order to remove calcium deposits and stubborn stains. A pool is first drained and the sides are scrubbed. Then a muriatic acid and water solution is applied to remove a thin layer of topcoat. This is done with manual scrubbing using an acid brush. The residue is then neutralized with soda ash before being rinsed away.
Why should a pool be treated with an acid wash?
Some pools have discolored surfaces or stains that can develop over time. For example, copper or magnesium stains can turn plaster from white to blue. A black plaster pool may start to look grey from calcium deposits. Oftentimes these types of stains don’t respond to scrubbing and require an acid wash to remove them. Also, pools that struggle with rapid algae growth and/or hard water will benefit from being drained, acid washed and re-filled.
How often should a pool be acid washed?
Because acid washing removes a very thin layer of the pool’s surface, it should not be an annual service. Too many treatments will result in a pool needing to be replastered. Pools with very thin, old plaster are not good candidates for acid washing and sometimes very deep stains will not respond to an acid wash. In these cases, replastering is a better option. A professional could do a test on the pool first to determine the effectiveness of acid washing the surface.