Hello, I'm new to this form and am a newbie when it comes to koi diseases. I recently noticed these bumps on my koi and was wondering if anyone knew what they could possibly be. I've recently had 3 koi die within a very short time frame. One died around a month ago and the other 2 a week ago but within 2 days of each other. I have checked my chemical levels and they are normal. I would really appreciate any help you guys can give, I'm completely at a loss and don't want to lose any more koi.