Powerhead to increase the airation, slowly discontinue use of salt. I unfortuneately killed several loaches before slowly getting the salt out of my tank. It is not necessary to have healthy fish. My Shoal right now sits at 36 CL's, and they share a 220G tank with several other fish, I will see some of them laying around pretty much all the time. When I (or whoever is freaking out) approach the tank, we get a look from said lazibones and he then darts back into the group. If your loach is not being responsive then I add my vote to those above, you need to worry.