Just got through acid-washing, in hopes of possibly avoiding re-plaster for another few years. I don't have any great "before" pictures handy, but the main thing we were after was to get rid of some dark (black-ish) marks on the pool bottom that kind of looked like someone may have run an automatic cleaner too soon after the original plaster job had been completed.
The good news is, those marks came out completely!
The bad news is, there are now some new marks & discolorations which are apparent right now. We hadn't noticed these discolorations, or if we did, they were very minor.
Maybe it's just because the pool is empty and they're really just minor imperfections that will be hidden once it's filled back up (is filling now)? Or is there something obvious here?
The pool won't be full again for another 24-48 hours so I won't know til then -- but if there's something I should or could try in the meantime, I'm all ears. If the stains end up being obvious after it's re-filled, then we're going to end up going for the Pebble Sheen (around $6-7k), so I am hoping they either aren't visible when it's full or that they can be removed.
Pictures can be found here: pool discolorations - Album on Imgur
(Note that there is some water in the bottom of the deep end of the pool in these pictures)