Beginning of a crack?

[Duke4Life]

Just noticed this about 10 inches above the bottom. Doesn't look like the other scratches. It is acrylic and not glass if that makes any difference.

 

[brandon429]

since its not at a joint and isn't linear ill call no crack, and that's some algae that has set in a scratch imo best I can tell

 

[Duke4Life]

since its not at a joint and isn't linear ill call no crack, and that's some algae that has set in a scratch imo best I can tell

It's not in the center either, off to the right if facing.

 

[Dr. Phil]

It looks like a scratch with algae growing in it to me... I have a few on my tank that look much the same.