I didn't think the salt would be super necessary, but wanted to be sure.
No, there's no copper, I just don't want him to get any infections if he has a bad biting episode. Sometimes he's fine then he'll saw it all down again. Makes me so sad when he does it, but he seems fine aside from it.
I'll write marimo down on my list...I want to have options.
And I'll be making the divider for the tank this weekend and be doing my best to make it impenetrable to those nerites. I don't want them getting any ideas, lol.