This was a guys rent house. The pool guy just up and moved without telling him. The owner said the pool had only been neglected for a month, but I find that hard to believe. I told him I'd clean it up if he bought the chemicals - and PAID me. This is what it looked like when I got there:
And this is what it looked like 4 hours later:
Nothing but 10% concentrated bleach and a lot of scrubbing.