As swimming pools age and are subjected to various factors they tend o stain. If staining of the pool surface has occurred, it can often be acid washed to remove algae and/or other stains. Acid washing removes a thin layer of the pools surface and helps refresh the look of the pool. We attempt to identify an acid concentration that will accomplish the task while minimizing strain on the pool surface. Some pool surfaces should not be acid washed due to their age or current condition.