Thanks
The fin rot is not getting worse, and hopefully it'll get better now that I've added the second dose of Kanacyn. Both corys and my betta remain active and are eating well. The white stuff I thought was fungus has pretty much cleared up now. 

You had said earlier that the white stuff is clearing up and that's a good sign. Don't forget that it will take a while for the fins to regrow, so if they are not deteriorating, it will just take a while to get back to normal.

I can hardly stand feeding frozen foods. I feel so bad for those poor little brine shrimp