Good afternoon. I am reaching out for help as I am unable to find a specialist in my area. I built a 21,000 gallon pond last summer. It has been an aweful Spring here in Ohio and we had a major warm up and then a great cooling. It has remained cool. Getting the temp up in the pond is so slow so I am hanging around 60 and we actually have snow in the forecast. I have a lot of alge in the pond and did two PP treatments in beginning of April. It didn't seem to help much. So I did an API Algefix treatment on Monday. But my bigger problem is this. I had a big beautiful koi in April become listless and hanging at the edge. I took pictures and went to a local pond store. He told me it was ich and the weather must have stressed the fish and to treat with ich treatment. So I pulled the fish and treated separately and he passed on day two. Now I have another one floating and I am completely at a loss as to what to do for a 21,000 pond with over 20 koi, and about a dozen babies that made it through the the winter. I have checked the water and all perimeters are on spot, it just looks like a swampy mess. The white and black koi is the one that passed the yellow and black is not doing well and I pulled him this am. Help, I am totally at a loss and am attached to these koi.