I'm not the metal person but I know if you raise your FC too fast when trying to sequester metals, it makes a big mess--that seems to have happened to you. Higher pH also seems to make the metals come out--and you raised pH rapidly.

Again, I'm not the metals expert but I think you need to bring your pH down to around 7.0-7.2 and let your FC fall into the 2-3 range for the sequestrant to work. You should do a search on Pool Forum for metals, especially posts by our resident metals expert, Mbar. That may help you.

Again, I'm not sure of my advice, but you can easily check it.