Help- any home remedies other than salt?

[kyari]

Sorry this was a long post guys! Hello. I wanted to introduce myself, my name is Carrie, and I was wondering if there are any home remedies I can use other than salt, until my order arrives.
We recently moved back to the states from Germany, hubby was in the Army, moved back home to Atlanta. We just purchased our first home, we have three kids, all boys.
The home we bought had this Koi pond already, so it was an inherited pond. The pervious owner just filled the pond and put fish in. Apparently the owner before that had abandoned his hobby and the pond was empty. He had 2 6 inch Koi and 2 6 inch goldfish. He told me all he did was drain the water when the algae got bad and hosed off the filter. It does have a bio filter with bio balls. He said most of his fish got picked off.
I have read tons of things, have books and all. I am testing the water, I have a 7.6 pH, 120 Alkalinty, no ammonia, no Nitrite, no Nitrate that the plants aren't taking right back in. My Nitrification cycle is great, my two colonies of bacteria are well established. One thing the previous owner did. I think it's a miracle the fish made it, if all he did for maintence was what he had told me. He certainly did not de-chlorinate the water. Yes, I know, miracle 4 made it.
My problem is other than some pick offs of my new fish right out of their 30 day quarentine, which I have netted the pond for now and it works. Is that one of the Koi he had is laying down. I know it is stress, the two goldfish just did this, than perished. The other Koi that was already here is fine. I know I have a parasite problem. He never treated the water or the plants he put in for parasites. I have salted the pond to a .3 just to help, I have a scope and Supaverm, Prazi, Malchite Green, and Formalin and Medi Koi all on it's way, it shipped yesterday.
I was hoping there might be another home remedy other than salting the pond and salt baths, to help out this guy. I hate to lose another fish. It's really sad, my children get upset, I do, I think even my cat does. She was not my predator, as I just started letting her out after I netted and she was still in doors, when my pond "raider" was raiding my pond. I just checked on him with a flash light and he is still alive, but just laying over, I know he won't make it if he doesn't get up, more parasites will work on him. I just pray I won't be burrying him tomorrow. He is in a little medical quatentine I set up. There are no visible parasites, so I am sure it is one of the micro scopic ones. Is it possible that he could be stressed out over the recent pick offs out of the pond? I just netted the pond 2 days ago, he was fine this AM when I fed, than this afternoon, laying over. I immediately did 40-50% water exchange, and de-chlorinated of course. I re-salted to .3 and my water is ideal on pH and all other tests, as I mentioned above. I tested my water about 1 hour after the exchange then again, this evening, about 6 hours after the exchange.
Any help would be greatly apprecaited. I am a new comer, but I have done my homework. Ironic thing is I am a PA (Pysician's Assistant) so I can doctor up you or myself, but the Koi I am still learning!
Thanks,
Carrie

[MikeM]

Folks are going to tell you that before treating you need to (1) determine the volume of your pond with a meter; and (2) identify what parasite is causing the problem. Do not rely on estimating the volume by doing calculations based on pond dimensions. It always seems to result in major errors. Remove all the water from the pond and filters (and the fish, too, of course). Then check your home water meter reading. Re-fill without using any water for anything else. When you are done, your home meter will give you a reliable volume measure. [In other countries water may not be metered, so this technique does not work.] Remember to dechlorinate and use an ammonia binder if you have chloramine in the tap water. To diagnose the fish, you really need to take mucus scrapings and view under a microscope. You may have access through your work. For koi health issues, I recommend koivet.com. Lots of useful information there. Some very knowledgeable people frequent that board and they love to help. Better, check the AKCA website and locate the club nearest to you. Many clubs have Koi Health Advisors who do tremendous volunteer work helping people. If work etc permits, you may well end up with a home visit by a KHA who can help you figure out your situation.