Thanks everyone for your support and good wishes!

Our vinyl liner is old and probably will need to be replaced next year - it's starting to pull away from the side and getting some cracks around the upper edge. (We're limping it along with simple repairs as long as we can.) So I was more concerned about killing algae than bleaching the liner. I do think it faded some, but it was already somewhat faded - the edges where the side meets the bottom are quite a bit darker. But it still has enough color to give the pool a nice light blue color and that's a whole lot prettier than green!

I started out with no CYA but now it's around 40 - have not checked it since last week.