Other than netting (which is now up, or trapping, what's the best way to
discourage raccoons?

Racoons are clever creatures. If they can, they will move the netting aside.

I believe you need an electric fence, if you're that worried about it.

Do take care to install it correctly. It's not something where you just
"wing it," the electrical has to be outside of the ponds water perimeter.

If the netting is heavy, and anchored, you may be okay, though.
There is a certain amount of overreacting that one can do.

Another option might be to go for a dog. Woof!

C//