HELP Garrett GTI 2500 w/treasure hound.

[U.p.digger]

Ordered Garrett gti 2500 w/ treasure hound. Will be here tomorrow. I live in the keweenaw peninsula of michigan. Old mining town. Not only do I dig the rock piles, I also hunt for float copper. Peices range from 1 pound, up to tens of thousands. And obviously their depth is both shallow and deep. The reason for buying the treasure hound is mainly for float copper. I'm just seeking advice on how to set up this unit for deepseeking some large copper. Sensitivity, etc.
Any advice would be greatly appreciated. Thanks!!