My pond is only 4 months old and my beautiful koi are dying left and right. I have a feeling that the last couple I bought on Sept 1st may have had parasites. I did notice a few white spots on my largest and then it seemed almost overnight it was covered in a white film. Every morning there were at least 2 dead in the skimmer basket. Some of them did not have the white film on them. I took a water sample to the local aqautic center and was told the water was perfect. I was told to try Anchors Away with a 25% water change and feed them Jungle Medicated fish food. That was Saturday, I have lost 4 more since then. Happy to say I did not have any die today but I noticed one of my 4" koi appears to have a sore on the top that has a fuzzy substance coming out of it.In early July I had a heron completely wipe out my pond and have since netted and restocked the pond only to have them die. This pond has brought me so much joy and so much pain!!! Its just like having kids again. Any help would be greatly appreciated. Pond is approx 2000 gal.: