What happened to my Primary?

I was brewing Saturday, two 5 gallon batches. Got my first one sealed and set aside and began wrapping up my second in record time. I went to get my second fermenter which is a 6.5 plastic bucket from Midwest, and realized that it had water in it.

My previous brew day was a week before and I must have forgot to dump my bucket. It had a mixture of Oxiclean and water that set in it for a week. I thought, no big deal, I'll dump it, give it some fresh Oxi and water, hit it with a sponge then StarSan. I went ahead and dumped it and started running fresh water inside, grabbed my sponge and noticed that the inside of the fermenter had a really rough texture. It doesn't looked scratched and has only been used once, but something happened for sure. I didn't want to use it and ended up fermenting in my bottling bucket as it was all I had available.

Any idea what happened? Did the Oxi/Water combo that was left in there have some type of effect on the plastic? The texture starts right about where my water line was and continues down, nice and smooth above it. I'm sure this thing was smooth when I used it the first time. Should I just toss the bucket?

use the bucket for something else, like sanitizing.

Don't toss it. I have had the same thing happen with oxy on bottles and in kegs. If you leave the oxy in too long it makes deposits on the surfaces. You can get it out with acid. I have used a strong Star-san solution(double dose) successfully a few times. I have also heard that vinegar and water will work too.

No big deal. Just don't leave oxy for longer that a few hours.