Changed from HOB filter to sump and now two of my fish are dead and my clownfish isn't doing well.

[cypike]

Going to add goby back to tank today, I have him acclimating to the display tank water currently

 

[cypike]

Clown and goby back in, goby’s fins were bitten by clown in my bucket but he seems to be doing ok so far clown is ok too

 

[cypike]

Not sure if goby is doing fine or breathing heavy

 

[cypike]

Everything seems fine now, not sure what went on. I saved all my fish except one. Thank you all for your help.