i'd say that's good, but it could take some time before you start to see it again. to control it from here out (if you're not sure about the shrimp) you could try a molly miller blenny or two.
http://www.advancedaquarist.com/2012/9/fish
they definitely eat aiptasia, and are good algae eaters, too.
Wow, if the rock looks that good in the bucket...
What is the water temp where this was collected? Do you know if there are any laws regulating commercial collection of this stuff?