The fact that a brand new batch of saltwater with oceanic tested at 650-700 leads me to believe that the test kit you are using is inacurrate. Oceanic is known for having high calcium levels, but not that high. ALso, you tested the batch at 1.20 sg which should give even lower levels of calcium. I am going to say that its probably the test kit. Borrow or buy a salifert test kit and try it on a new batch of saltwater. If you report the same results at 1.20 specific gravity with the salifert kit then there it is probably anohter bad batch of oceanic.