Recently our swimming pool service guy advised us to have our 8-year-old (salt system, sand filter) pool acid washed. He drained it and acid washed it. He told us it would darken the pool a little. The pool is plastered, dark and medium gray bottom, which previously gave it a medium blue color when filled (due to sky reflection etc). Since it's been acid washed and refilled - and all chemicals adjusted- it appears more green than blue. It's not algae, just a darker color and really too green. It also doesn't have the clear sparkling look that it once had.
What would cause this? Can it be corrected?