Fungus problem?

Hey guys, I have been checking out this forum a lot lately and have gotten some great tips on stuff, so I was hoping you could help me with this. I have two gold severums, an lda32, and three other smaller fish (about 2in each) in a 65 gal aquarium. I inherited these from my dad recently (about a month ago). I do about a 10% water change weekly, and have begun to add salt with each water change (in attempt to get the tank up to about 2%-3% salt, instructions on back of canister say 1tbsp for 10gal). I noticed in the last few days one of the severums has a white patch on its side, that first appeard to be an injury from swimming into a rock, but now it appears to be "hairy". Is this a fungus and how would I get rid of it? Thanks for any info anyone could provide. I have a couple pics, but they aren't very good, and only show a white splotch on the side of the fish. I can email those if anyone would like, and I'll keep trying to get some better ones. Thanks.


Jeff

I did use a testing kit, and here are results (sorry, forgot to include this in first post):

pH: 6.8 (stable)
ammonia: <.5ppm
nitrite: 0ppm
nitrate: 40-80ppm

I proceeded to do a water change, about 30%, with ~3tbsp of salt added to new water.

Any ideas? From what else I have been able to read, this sounds like a fungus problem, that could be aggravated by the high nitrate levels. These two severums are very "jumpy" at times, and it would not surprise me if this particular one swam into a rock and scratched himself, then the wound became infected. Does anyone have any reccomendations as to what to use to treat a fungal infection? Thanks.

Jeff

Well, here is what I have done based on reading through some of the other posts dealing with fungus.

I have set up a 10gal (5gal from my current tank, and 5gal new water) that has been treated with Mardel Maroxy, and placed the fish with the fungus in here. I have placed an aerator in this tank to keep the water flowing. Hopefully this will clear up the problem. I would appreciate hearing from others who have faced this problem.

The Maroxy says to only leave the fish in this treatment for 5 days maximum, and the directions say to use 1/2 capful for every 10 gal. Is this 1/2 capful per 10 gal per day? Thanks.

Jeff