Roger - Believe me, I have thought of that too. My biggest fear is that I may be causing more harm than good. A perfect example is the raising heat scenario. I read that raising the heat gradually until it's in the high 70's or low 80's can help the fish fight off certain diseases and parasites. While that may true, I also failed to realize that the higher the temp, the more lethal even the slightest amount of ammonia can be. So I may have actually killed fish by doing that!
I am pretty disgusted by this whole turn of events. I had the most beautiful collection of fish in there, and now I have about 7 left, and only a few of those look active and social. The rest stay hidden or just sit alone by themselves (which leads me to believe that they need help).
I have vowed to not purchase any more Koi or ornamental fish EVER for this system. If I need more fish, they will be cheap feeder fish, and I will be sure to quarantine them for a week in a salted hospital tank prior to adding them to my AP system.