A few days ago my tank was dirty and I said to myself it was time to do a water change, and I look at my goldfish and see she has a red almost veiny looking burn? I believe it's an ammonia burn..not sure tho. So I threw some API Quick Start in the tank overnight, it seemed to lessen a little bit, but then it went back to how it looked. I do the change and put the API in again, and did a one day fast, still no change.. Any thoughts? Here's a close up, she hates when I try and take pictures of her.