| Interesting stuff Carl but I want to point out that my house is not new. It was built in the 70s. This is a problem that has been steadily building over the years until it finally wiped out their immune systems. Also my problem is a combination of high copper AND zinc levels which is a bit different then you see talked about on the web. Mostly you just hear about copper. Another item to point out is that in many cases when its a copper kill off it usually is not gradual like it was in this case. I think in this season alone I have seen every major skin problem a koi could have all in one pond and in some cases on the same koi. In hindsight knowing that I do water changes every other day and that my filtration system is working correctly I should have checked the water for heavy metals long ago. Another clue would have been the health of my wifes um longfin koi in my 3rd pond. I flush that filter maybe twice a year and almost never do any water changes. In fact about all I do is top it off but mostly it gets its water in the form of rain. Never a problem in that pond (except that it has longfins in it). Tough lesson and one I hope others will learn before it gets as far as it did in my ponds.
__________________ Koi-Unit |