Thank You Butterfly.
What is a trichlor puck?
I will try to send a pic later after it gets light. I assume you mean of the black spots or of the pool itself. I will send both.
I have a salt water pool with a Pebble Tec finish. I have to small areas of what I think is Black Algae.
Do any products work? What should I do? How do I know for sure if it is Black Algae. It does look like it in the picture that I have seen.