There is an issue with the water flow here, I'm afraid. The loach should have a good current, that is what it naturally lives in and thus expects (see the "Habitat" and "Maintenance" data in the SF link in post 8). The term "obligate" under the Habitat conditions is very significant...in biology, the term means "able to exist or thrive only under a certain set of environmental conditions," and while a fish may "live" that is not the same as "thrive."
Unfortunately, this will not suit the Ember Tetras (
Hyphessobrycon amandae) that like a quiet environment.