Hi Joe;

I've never seen a bright green reaction, either.

Yellow, yes. Orange, yes. Cloudy, yes. Brown and clear, yes. Brown and cloudy, yes. Even purple, yes. (Boy, that's a wild story I should tell sometime. BIG boo-boo!)

Bright green? nope.

Odds are it doesn't matter. You've got a mess, but it will probably eventually clear up with chlorine bleach and sunshine.

I would cautiously add bleach -- the peroxide will keep destroying it for awhile -- till you can hold a residual overnight. Once you get there, you'll have to start shocking the heck out of it at night, to get rid of the bromide / bromine.

By the way, if you can reach any of the spots, scratch one with your fingernail. Then, spread the goo from under your fingernail onto a white card. If it's black algae, the smear will be dark green. No smear, or nothing under your fingernail, it's not black algae.

Oh, and if you can dig that shock container out of the trash, and find out exactly what was in it, that would be good to know and post.

Good luck,

Ben
"PoolDoc"