Hello all, I recently bought a home with a large pond in the yard in the area of 2500 gallons. With no pond experience and notes from previous owner on how to care of the pond I turned to the Internet and the local pond store for help....I had a test kit and my water levels were perfect. Suddenly 2 large koi stopped feeding and within 1 week died. I called twin pond farms here in Howell Nj and within seconds Gary new I had a parasite issue. It turns out all the signs were there but me being a Newbie I did not notice. If you find your koi hanging under the waterfall , flashing or scratching against the rocks and occasionally jumping out of the water treat for parasites immediately. I am currently treating for parasites so please wish me luck...