Welcome aboard. As others have pointed out, these ideas are more for a dug in long term situation, but that's not a bad thing.

For heavy metals, proper filtering is the only way to go. Layers of charcoal and clean sand is what comes to my mind.

As for lacking the cup... *leans close, whispering* Carry a folded up piece of aluminum foil in your wallet. If anyone asks, do as I do- tell them it's the money used at home, but unfortunately there aren't normalized rates of exchange yet. Maybe after the Solarians bow down before their proper superiors and except their place in the Galactic Empire, that will change.

And it makes a useful cup.