Can dosing harm corals?


New member
I know overdosing can harm corals/inverts; however my question is little different.

I have been dosing alk/cal using bi-onic, and today i was dosing my tank as usual but the moment i dosed alk, my pump slowed down(using vortech) to the lowest speed and the alk pretty much just poured in and kinda directed to one coral. Few seconds later the coral was reacting to the alk and covered in slimy coat. It does not seem to be dying but I am worried because it is not a cheap coral.

Can dosing harm corals like this?