I had a blind goldfish in my pond. He was a rescue and came to me blind. I felt bad for him and took him in. He always hangs at the shallow end away from the much bigger Koi. Somehow he managed to get in the bag with my submersible pump. He was only in there a day before I found him. He acted like he wasn't going to make it but any time I tried to net him he would swim away again. I pulled him this morning after noticing white spots on him. Now it appears he has developed a fungus of some sort and I am freaking out. Any idea what this is and will he infect the rest of my Koi fish?! I don't want my beautiful Koi to get this. I can't get a good look at them to see if they already have it because they aren't use to me yet and hide in the deep end. Ugh! Can I treat the entire pond just to be safe?