Paling Parrot Fish

My parrot fish are under some stress right now, but one of them is having the roughest time. He's usually a ruby red, but he's losing his color in white patches all over his body. It started with the area before the tail, but he's getting patchy all over his sides now. I've had parrot fish lose their general color under stress, but never in clearly defined white patches. It's not fuzzy; it's almost like blood can't get to those areas. Other symptoms include floating on top of the water (it's upper fins are above water) and more effort in breathing. He can still swim downwards and eat, but otherwise spends the entire day floating. I haven't seen him poop yet; he's looking a bit bloated/fat, but he doesn't have other symptoms of bloat.

Parameters are 0/0/~40. Temp about 75F (but may get hotter since Southern California weather is currently spicy).

Some background:
I came home to find a new fish mixed with my blood parrots which my father called a "king kong parrot fish." I've never heard of it and I certainly didn't like it since out of all the fish in the tank, it's the only one capable of biting. Also, my father failed to mention that it had no tank mates in the LFS; oh boy it was very aggressive.

Seeing that there's more bioload in the tank, I made a large water change. The next day, all of the parrot fish (except for the king kong) were floating near the top. I incorrectly assumed it was lack of oxygen because of the new fish; I didn't get to the root of the problem until two days later: our water softener no longer worked which made the water change spike the hardness. The water softener has been replaced; the water should be more stable now.

The problem:
My parrot fish are still recovering from the mess, but one's condition seems to be worsening as mentioned above. I know it's recoverable because another had the same symptoms and is gaining color back.

I want to quarantine the struggling parrot fish to control its parameters better, but the quarantine is currently occupied by the king kong since he chased the smaller fish until they literally could only float lopsided from fatigue. I am currently unable to return the king kong; it may take a few days.

Should I add the king kong back into the main tank to quarantine the pale parrot fish? It'll risk the two smaller fish being chased. I've tried to add more cover, but the king kong is simply too fast. When I walk past the tank, they come out of hiding and the king kong chases them.

Otherwise, I'm just not sure what to do. Skip a day of feeding? Add meds? I've been considering some of the "stress coat" stuff since he's partly out of water for a large part of the day. Any help would be greatly appreciated.

A water change is due in the morning. Anything special I should do then?

Thank you.

 

Small update: checked on the fish after hearing some splashing. It seems I was wrong; some of their conditions are worsening, just at a slower rate than the one I'm most concerned about. What's going on in my water?! Hopefully a water change in the morning will help. Their movements are erratic, but they're not trying to scratch themselves on surfaces.

 

I dunno much about Parrot Fish, but I'm thinking that new King Kong Parrot might have brought with him some nasties along with the aggression since it didn't have any tank mates. Does the King Kong look anything like this:?

Might have to quarantine the King Kong until you can get it sorted out.

 

Yeah, he does look much similar to those fish than the parrot fish in the tank. He should be returned tomorrow afternoon (hopefully).

I'm also thinking he brought something along. The other fish seems to be struggling with something while he's totally okay. He's quarantined, but I've no clue what's in the tank nor what's happening in the tank. Some are getting better, some are fluctuating, one seems to be immune to whatever's going on.

I've dumped in some SeaChem Prime, accidentally overdosed Stress Coat Plus, and added some more aeration, so hopefully they've got good conditions to recover. Not sure what more I can do. Feed peas maybe?

On another note, my resident snail pests seem to be missing. They usually climb out of the underground filter during water changes. Oh boy, incoming bioload!

 

Update: they're getting better! Sort of. I guess I'm doing something right.

One of my fish seems to move erratically, like he's trying to scratch a side of his face against glass and ornaments. I can't see any markings or reasons why he would act so itchy. He'll only stop once he tires himself out, but at least he'll still eat!

Maybe it's the Stress Coat? He was acting erratic before, but now it's a bit more pronounced. Some of them still float with their upper fins sticking out of the water, so I'll have to keep the Stress Coat in a bit longer.

 

Hmm, have you thoroughly checked the water parameters just to be on the safe side? You've put a lot of different chemicals ( I know to help the Parrot fish), but it might be masking something else ya know?