I never really tried to treat him, I didn't really have place sufficent and I have no mney for meds. I am not really happy about it, I actually got sad while writing this. I'm just saying what happened. I really have no point, I just posted it. I wanted to share it. We have ahd that koi for about 4 years. We havn't had any luck with the pond cause I actually think the neiborhood cats are some of the main causes for all of our large goldfish and koi to die within a year period. I am gonna try and persuade my papa to do a full cleaning of the rocks (substrate) cause of all the built up poo and debri. The filter is way past it's prime, and we have no money to replace it. The only reason we have had the pond going good till now is because my Papa's old boss would give my Papa extra things that came in. The pond, was free cause it had a chip on the siding and was thrown out. The filter, extra so, it was given to him. Slate for the waterfall, free cause it was to small for whatever project. He was layed off and has no more free equipment. I his job now, he's doing the same work but, the company is cheap and won't hand out anything.