Old leaves that are damaged will stay that way most likely. Look at the new growth that will tell you more. Also like the previous poster said wait like a week or so and start back on the feed, maybe start at 1/4 dose. Now if the plant shows yellowing sooner than a week it wants to be fed. Good luck, flushing IMO is something that people should do more often, not just when there are problems.
Hey lowryder, I see your a Dallas fan. LOL it's all good, I'm a Eagles guy born and raised. I know we aren't supoosed to do sports but some friendly razzing here and there is fine with me. This takes a lot of heart, just so you know what kind of guy I am....good season. LOL, like I said it's all good.