Thanks for the info guys. Still looking into what kind of fish I might get to live with my shrimp. My shortlist is pretty much Bumblebee Goby, Rasbora or Sparkling Gourami.
Rosie red minnow... Hmmm... How big does that species get? I heard somw minnows can grow up to 14cm long -- which would probably be big enough to make short work of a ghost shrimp...
I've read that they have a reputation for breeding loads, a bit like guppys. They look like very attractive little fish though, should be fine in anything 10gals or more based on their eventual size and activity levels .