Is this just a scrape?

I was doing a water change and I noticed the green/brown rainbow female had this on the tail which I assumed was just a scrape. I decided to move my QT clown Loach over.

After the water change I noticed a Dority make had a mark on his tail too. This must have just developed in last 24 hours as I look them over everyday, all though not as thoroughly the last few days.

I probably would've delayed moving the clown Loach over had I noticed two fish had this issue.

Thanks for any input. I was happy that I moved my clown from QT as he's enjoying being with his own kind again but now I'm worried about this tail issue

 

Yeah, I think they ran into something. It's a lot less noticeable as you can see below. With the female green one, I can't even tell which Fish was the one with the mark.

These rainbows are clumsy. It seems like once a month, one if them is managing to hurt themselves.

 

Thanks everyone. Been doing twice weekly big water changes ever since one of the other rainbowfish hurt himself 3 weeks ago. I might just do every 3 days till this is cleared up.