ID Please

[Brisk]

What is this on my glass? It barely moves and I've only seen it come out when lights are off.

 

[theunderwaterarchives]

Looks like a flatworm to me. They come out when the lights are off, if you only see one in there it's generally pretty harmless.

 

[Brisk]

Looks like a flatworm to me. They come out when the lights are off, if you only see one in there it's generally pretty harmless.

I saw 4 at most so far in one night.