Urgent Please Help! ?!?

My tank has turned for the worst in the past 24 Hrs my other half toped of my tank and all went to hell my salts sky rocketed my fish instantly started to die So as soon as I could I did a semi water change. Now all my levels are great and I am left with my clown and a chromy the pet store said with the water change my fish should be fine.But know my clown looks like he is loosing his color and has white spots covering his whole body and seems extremely ill (so sad) I want to help him he has been with us for a long time I can't stand to see him die. FYI: the other fish that is left is fine, prior to my catastrophe my clown was in great health IDK what could of happened besides the obvious water issue. If anyone has any suggestions please let me know! !!!!!!

 

Pictures would really help. My first thought is ICH of course. You could start up a hospital tank and treat your clown there. There is also a hypo-salinity treatment that you could try as well. Research it first, but the very basics of it is that you use a salinity of 1.020 or maybe lower. From my understanding, ICH hates low salinity levels.

Something else that will help us help you is if you could post your params and how long your tank has been up and running.

 

Great advice. Only thing I would suggest is if it is ich you may want to gradually lower the salinty since the clown recently had hypersalinity

 

Marine Ich is an opportunistic parasite, meaning any stress like sudden changes in parameters allows it to gain a foot hold.

SG target to treat marine ich is 1.009, anything higher and treatment is most likely ineffective.

The ideal situation is to have a QT up and running, but this is usually not the case and sometimes not practical. The stress of QTing an already sick fish is sometimes enough to speed up it's death. The placement of a sick fish into an uncycled environment and sudden change in parameters adds to the stress.

IME those cases where you can correct the stress ie: parameters, and where the fish is still eating it's better to leave the fish in the tank. Unless you are going to treat the display for disease it seems pointless to treat in a QT only to return the fish to environment where marine ich is still present.

If you decide you want to aggressively treat for marine ich please research it's life cycle, other wise it's pointless IMO.

Good Luck.