I would recommend being careful about Bacter AE. A lot of people swear by it, so it works great for many! However, it has also been known to kill shrimp, even potentially an entire colony when it was fed at either recommended or half dose or even fed at all.
It's believed that it removes oxygen from the water column, thus suffocating shrimp.
I've never used the stuff personally, but there's plenty of anecdotal data out there. That is, it can vary from person to person, perhaps even colony to colony aka type of shrimp vs type of shrimp.