On the Equinox, bottle caps are not much of a problem anymore if you have the latest software (3.1?) and use FE2 @6 or so. Aluminum junk is a different story. In 50 tones and with the horseshoe on, you can sometimes tell that it isn't a round target, but, other than that, you just have to rely on the sound and size of the target. I choose to just scoop all non-ferrous targets (and some iron ones too) at the beach. It's not that big a deal IMO. Now, in a park, school, or other turfed areas, that's a different story. I cherry pick those sites and pretty much forget about I.D.'s in the teens, except for 13. I often do dig solid 12's and under though, and find tons of foil, with the occasional gold item. If the signal jumps around, forget it. Gold is very stable and the I.D. numbers stay rock solid for the most part.