Many of our customers have tried those ‘all-purpose’ stain removers, only to find that they were too weak to actually remove any stains. For others they contacted other pool service providers who recommend acid washing to remove stains. While this may remove some of the stains, there can be serious problems caused by the process of using acid on your pool’s plaster. Acid washing removes the outer layers of the plaster and may not do any good. Not to mention the act of draining your pool alone can have unplanned consequences. If you have any doubts, read the waiver that those companies have you sign. Add to that the cost of having your pool acid washed, in most cases it ranges from $750 to over $2000. Then you have to add the cost of refilling and re-balancing the water.