Dale, I have been staring at your post trying to answer your questions for the past couple of days, but I just can't seem to answer any of them. Could you please provide me with the answers?! Do wild bears crap in the woods? Hmmmmm, I don't know.......I am going to have to go into the woods to look for wild bear crap this weekend to answer that question! LOL! You crack me up!!!!!!!
Anyways, all joking aside, the reason why I started this thread was because of my naivity in thinking that if all the water parameters such as pH, ammonia, GH/KH, etc. are met then the water quality should be good! I was being too much of a pure chemist because I kept on thinking that tap water consists only of water (H2O) and chlorine. I didn't think that it contained other essentials that the koi could use up.
Also, now I have a better understanding that, in addition to waste, koi also secrete pheromones which could decrease growth rate. Now, rather than changing water because everyone's doing it, I know why I have to change it!