Need Help.. Fish Dying and dont know why?

[WJC05]

I need help. My fish are dying off one at a time and I cant figure out whats happening. I havent added any fish in a long time and the only thing I can figure out would be a bad feeder. I never have sick fish so I dont know much about it. I have added melafix and salt and did a partial water change.

Whats happening: Some of the fish are almost stuck at the top. They will swim to the bottom then they float back up and their backs are out of the water. The catfish just look horrible. I took some pics and need some help..

Heres the pics..

 

[WJC05]

So far Ive lost my large planiceps and my biggest chancho but Im afraid Im going to lose many more

 

[pitbullfish]

probably a parasite from the feeders. sorry for your losses hope everything works out for the better

 

[Newt]

Holy crap, that cat looks terrible!

Looks like a really bad bacterial infection.

 

[WJC05]

Any clue on something I shoud be dosing besides melafix and salt?

 

[Akin]

That catfish looks like it has Velvet. Here is a link to information regarding velvet ( http://freshaquarium.about.com/cs/disease/p/velvet.htm ), I hope you find this information helpful.

 

[WJC05]

I dosed some copper safe earlier. I know copper isnt the safest of medications, but everyone is going to die if not taken care of...

 

[rba718]

Wow man, I hope they get better.

 

[fishdance]

Looks like ammonia toxicity to me. I hope you are not still feeding while the fish are sick. I suspect there is a lot of uneaten food in all that bottom rockwork/clutter or perhaps some dead fish body. A quick ammonia test will confirm but I would be water changing and making sure the tank is clean regardless.

 

[princess]

wow the cat looks really really bad thats so sad. if you figure they are gonna die anyway i would do a serious waterchange strip the tank out to get trapped poop outa the gravel or rocks or whatever. i'd just take it allll out