I agree it looks like he scraped himself. He was scraping against the plastic plant like he was itchy. That sounds like good advice. Water change for 10 days is 20-30%of water? I Know that Adding a lot of salt is not good for a goldfish.
I have a goldfish that is a over a year old and so he has been pretty hearty. We just had our power restored after 7 days of heat and the aquarium Water was very Dirty. The scales look abraded on the fish. I did what you suggested above with water change and added salt. Should I add salt every...