From the symptoms that you describe, I would say that you do not have ich. Ich will look like small white spots which are most easily seen in transparent fins. It can also look like salt on the body. Search for pictures on the web. It alse will not cause large open wounds on the fish. It is possible that the fish had ich and while scratching themselves on rock or gravel caused a wound, and then bacteria secondarily invaded and caused a larger problem.
If you want to get frags, just remove your fish to a quarantine tank. Try your best to determine what is the cause of your outbreak, and treat accordingly. DO NOT TREAT THE DISPLAY (if you want to get frags any time soon). DO NOT TREAT THE DISPLAY EVER WITH COPPER!! Copper can bind to the rock and gravel, and then if later the pH drops too low, it can be released back into the aquarium killing any inverts. It can also be released at levels high enough to kill the fish.
It is nearly impossible to keep diseases out of your tank. Just to many pathways for entry. Quarantine is probably the best method to reduce the chances of it getting in your tank. The other is to keep the fish as stress free as possible. Stress is a major factor in fish disease. Unstressed fish can normally fight off infections or parasites before they become a problem.
