Scottish koi club

Did A scrape on one of my fish as it stopped feeding and was flicking so i did a scrape and found a fluke so i sent away for fluke m. i dosed the pond and a week later did another scrape found nothing so did a water change while i was going a water change the fish i had scraped kept coming to the top so i put some food in the fish was feeding but after the water change all the fish are on the bottom and not moving much they are still feeding except for the fish i scraped. Has anyone any idea what can be wrong tested water all ok ph a little bit higher than normal.