What is the salinity/specific gravity, nitrates, and pH? When my lion stopped eating, it was due to my specific gravity dropping all the way down to 1.010. Me being stupid, I actually trusted my hydrometer, which was falsely reading 1.022.
I would test your water at home, and then take your water to your lfs to see how they read there. Get your lfs to test your salinity with a refractometer and see how it reads (if you do not use one already).