Forgot to mention, but think you have figured it out, I run the discriminator set to the 0 setting and listen to all three tones; that's where the very slow sweep over nails will drop to the lowest frequency tone.
I love the CZ on the salt water beaches. I think it was Dan-PA who posted previously about running in the normal mode unless you get falsing and have to go to salt mode ... I usually just set it to salt mode, ground balance over the wet sand and go. With the CZ6a I'll work from the shallow, ankle deep, suds to the dry sand and not play much with the settings. I generally use the biggest coil I have for the CZ6a at the beach.
Bottle caps are mostly like nails, if you sweep real slow they start to go low tone and when you speed up a little they are high tone. The newer coated ones sometimes don't go low tone at all, so I frequently scoop a fair number of bottle caps at the beach.
Sounds like you are doing well and have some good sites to hunt with the silver you are finding.
Enjoy!
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