Planted Tank Guru
Join Date: Sep 2006
Location: Northern California
No, I wouldn't do this to separate two Neocaridina species of shrimp.
Baby shrimp are TINY. And no matter how creative you are, they're more creative and will find a way of getting through the moss wall. With flexible mesh, you can't be certain that the moss will cover every hole in the mesh.
Unless you don't mind hybrids, I'd use either panes of glass/acrylic to separate the tank or just go get separate tanks. With the panes of glass, you could theoretically attach the moss to either side with a tiny dab of superglue and let the moss grow to cover the glass. Like Glenn said, with this type of setup, filtration on both sides of the divider is obviously crucial.