Help!!! My water is Black and liner looks black & burned

[waterbear]

oxidized copper (the black and grey staining you see) is one of the hardest ones to get rid of. I am not sure it can be done safely in a vinyl pool without destroying the liner! (I assume you have a vinyl pool because you said you have plastic wedding cake steps) I would contact Jack's Magic www.jacksmagic.com
for advice on what to do. I wouls also STOP adding the copper sulfate, find a store that does test for copper (and if it's over 1 ppm DO NOT GO IN THE WATER!) or get a copper test kit (not strips) from Taylor or LaMotte and test it yourself.

In any case I wouldstart draining and refilling the pool to get the copper levels down.

You can try ascorbic acid to see if it will help but I don't think it will (hold a vitamin c tab on the stain and see if it goes away, if it does you might be able to use ascorbic acid to remove the staining but this usually does not work on oxidzed copper stains)

YOu might have to replace the liner and the steps.

Even in a plaster pool the process to remove this type of staining can take weeks to complete (or the pool is acid washed in really bad cases)