Vitamins

I was trying to vary up the diets of my Oscars and they have apparently not getting the vitamins and such that they need and one has developed Hole in the Head. I have been doing water changes to make sure I keep the nitrates down but is there anything I can add to their food to give it some more nutrients for them to kind of power-load them with vitamins and minerals to boost the immune system to get this Hole in the Head stuff straitened out? In saltwater I would probably soak their food in Selcon but that's marine only if I'm not mistaken. Any ideas?

Update:
In case you are wondering I stopped varying and went back to strict Hakari Gold which they always were healthy when I did that. It seems to be helping a bit but not the results I was hoping for. It is apparently a slow process to heal a hole.

 

Try garlic, that is good for both fresh water and marine. Also you could add a little slime coat to the water to help fight off infection. There is medication for the treatment of the disease, Matronidazole I think is what it is called.

+1 on the pellets as feeder fish are bad news, also you can feed crickets, blood worms, earthworms and mealworms. Mine really liked blackworms, but that was like 20 years ago when I had Oscar's in high school. Also, the glass shrimp were great for the Oscar's as well.

 

When I was younger I used to add melafix, half dose malacite green, stress coat, and a crushed up flinstone vitamin to the water a few tiems a week. No clue if it did anything nevermind good but the fish grow like mosters and fast one of which was an oscar. Never had HOH lol