FYI: Just before giving up and draining the pool, the wife used the Lslie's Ultra Bright Clarifier. It's been working GREAT. Every few hours we need to pull the filter, clean (the filter is feels 2x as heavy when full, it's really picking up a lot of stuff!!!) add more clarifier / repeat. Gone through a whole bottle now, and the pool's turned blue overnight. Just using the last of the bottle now, and I think it'll be perfectly clear after this application. If not, we're going to grab some more, and I'm confident we'll be swimming this afternoon