Bergia Nudibranches in Calgary?

[DaveWilson]

For a while we've been attacking them with the lemon juice and a needle but they just seem to come right back, and they seem to do so faster and bigger than the last time. We were sold a copper banded butterfly fish to help take care of them but he hasn't touched any of them yet, and we've now heard that they can be a difficult fish to take care of. We've heard really good things about berghia's, but apparently they are pretty hard to find it seems