Tank not right after Water Change

[likwid]

I noticed my salt levels were extremely low, and it had been a while since I did a water change, so I did a fairly big water change in my 10 gallon tank, about 60% or so. I added a lot of salt to even everything out, and now the salt levels are fine. The next day I noticed my clown fish would not eat at all, which is strange because he is a pig and always eats right away when I feed him. He also just stays in the corner of my tank by the heater and rarely ever leaves from that spot. All the little feather dusters on my live rock seem to be fairly frail and half do not even come out any more. On top of all of this, the hair algae and other green algae that was growing on my live rock are now turning brown. I did a test and all of my levels are perfect. Is this from the sudden change in salinity and the major water change? Is there anything I can do now besides just wait it out? Anything to get my clown fish to eat? Thanks