Clownfish not moving

[sam_tabussom]

Hi,
I am new to keep salt water fish, but I have kept fish tropical and cold fish before. My clownfish which I’ve had for 3 weeks is not moving after I’ve done a recent water change. He is sitting at the bottom of the tank and I do not know what to do
Please help so he doesn’t die
Thanks

 

[Sniperhank]

Can you tell us more about the system? What are the current parameters? Did the water change match salinity?