Blasto frag tissue loss

[Brian1f1]

Hello,
I’ve had this frag from WWC for about three weeks. I noticed a spot on this little blasto frag (a “fallout”), a few days ago, but it was tiny and looked fine the next day. Tonight I noticed what seems like tissue loss in the same area. It’s expanding normally though. I made it retract to get photos both ways.

This is the area I normally target drop roids on, I wonder if it’s possible that irritated it?

All else, including neighbor blastos look well. Any blasto pros have an idea of what could be causing it? No jelly to speak of, no worms I can see, wonder if a crab or someone nipped it?

Thanks as always!

Inflated

Deflated

 

[Brian1f1]

Occurred to me I also changed the flow pattern about a week ago. I think that area might be getting moderate or slightly higher flow now off the back glass. Can that cause that kind of damage?