If the fish seems to be better, just continue give it as much fresh, conditioned water as you can, to finish flushing out the salt. Carp are not salt or brackish water fish.

But red streaks in the fins would indicate a bacterial infection, so lots of fresh, well oxyigenated water and a broad spectrum antibiotic would seem in order.

I hope your pet will be better. I have hundreds of valuable tropicals, but my pet, is a huge, fat, useless Goldie, and the only fish I have, with a name.

First sorry to hear your guy went though this.. Sounds like you liked him a lot (her). (I know how it goes)

Parrot, I had just done tons of research on salt, as I had a ph problem and found out this.

Salt unless pure NaCI can have other agents (even natural ones as in sea salt, mag/cal so on) that can raise ph so rapidly as with salt dips it can cause harm. (I did a salt dip and have used this for decades and a gourami died in seconds and now I realize it might have been a huge spike up on ph rather then the salt, not that much salt.) (I mean from 7 to 9 or more in a nano second!)

I am tired now but will try to find those articles on salt or remember what is salient here for your situation.

A certain level can cause osmotic damage or even 'burn' fins so on. But many fish can tolerate salt if increased in doses slowly, eps those like gouramis, and bettas others who were from this background as opposed to say hatchet or neons. The key word is slow, meaning over days if for illness treatment or big problems arise.

If memory serves though, just the proper amount stimulates the slime coat (to help rid that layer of parasites say) but too much causes problems, ie stripes the slime coat leaving the fish vulnerable, in addition to any stress caused by electrolyte imbalance and or ph spikes from other agents (cal/mag) in non pure salt.

Looks like he got striped too much, and then bacteria set in. And osmotically stressed to boot. That slime coat is their main defense to all things nasty. Now is the time to be gentle. First thing comes to my mind is to use some sort of fake slime coat, such as stress coat, or any with aloe vera so on... He need protection much like a burn patient, to both prevent bacteria et al from invading but to more importantly keep his osmotic regulation in tact.

aybe some one knows of any other better product for this. I just used to use stress coat and now most conditioners state that extra can be used for slime coat, but maybe aloe vera in stress coat is better? At this point I'd think any thing better then nothing, like a layer of protectin until he can grow his own.

I would put him in tank with same water, (to keep things stable) his filter and bare so you can keep it super clean until he improves. (with conditioner of course) THey can survive a while without food which will be a mute point if his slime coat stays damaged. So wouldn't worry if he fasts a bit, but maybe soak his meds in food so bacteria(onces in veins and vessels hard to combat) can be attacked through internal meds. (try to get him to eat this, and clean up after if he doesn't or leaves any behind)

Take stuff off bottom daily and this will prevent ammonia build up so on as well. Plants or silk plants for his security and they can be cleaned daily with hot water (fake of course, lol) to keep bacteria at bay. He has no coat so extra clean water if that can be done as all water has something in it.
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From site:

Basically, salt will strip or re-stimulate (depending upon the concentration) the slime coat produced by the fish, increasing antibodies and making bacteria, fungus, and parasites more vulnerable to medications such as antibiotics or fungicides.

My add on: you over stripped i.e. too much salt and no slime coat now, so bacteria could invade.
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The ph issue is what started my search. I switched to pure Kosher salt which is pure salt with NOTHING else in it. Not a bit of ph rise. I can now increase my salt without increasing the ph. Who knew. Then I found many other interesting articles on salt.

Hopefully his gill area (fine filaments) are not damaged, if they are he will slowly suffocate to death. I would (again) maybe suggest stress coat or some other natural slime conditioner along with bacterial meds starting with gentlest not sure how he can take them now.

In regular situations I would suggest a mild salt dip, but not now.

What type of salt did you use. How much. How administered, all at once (never!) or dribbled slowly over time (days often for treatment of diseases). It again affects their osmotic cell regulation so much complicated stuff occurs inside the cells not just on their surface. I will try to find the info later.

To recap: Keep him dark area, plants for security to lesson stress... clean clean water, gentle partial changes, and stress coat to add some fake slime coat along with bacterial meds. Good luck and sorry to hear it. Best Sherry

Ps. I agree red streaks bacterial or other injury such as what he experienced, but basically hemorrhaging of blood vessels. (bacteria invade blood capillaries and cause them to bleed further, inflamation so on...) The following ref to bloody patches due to injury sounds like what you describe around his head area. Can obviously be combination of many things.

"Bloody Streaks-Septicemia is a bacterial infection that causes bloody streaks or patches on the skin of the fish. It should be treated with an antibiotic. Bloody patches may also be present due to injuries or parasites such as fish lice."

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Bacterial Infections: Inactivity, loss of color, frayed fins, bloated body, cloudy eyes, open sores, abscesses, red streaks throughout body, reddening or inflammation of the skin, fins or internal organs, bulging eyes, difficulty breathing.

Ragged or decaying fins.

Finrot

Check pH and correct as needed. If level is normal, use OTC antibiotic for fin or tail rot.
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Another earlier garden link re salt....(but I only use Kosher pure salt now, just decades of experience)

http://forums.gardenweb.com/forums/load/aquarium/msg062244164624.html

I agree about adding aloe to help replace lost slime coat and am contrite for having failed to suggest it previously, but if you can get your hands on a live aloe plant, it's fresh sap will be even better than what comes in a bottle.

Then, if you ever get sunburnt, you can use it on yourself.