Flatworm?

[Joiningsession]

Hello, was about to transfer some corals from one tank to another and start breaking down the old when for the first time ever I noticed flatworms… the tank has been neglected for a couple months and now I’m not even sure if I want to transfer anything over. Where are these and what routes can be taken? They are a “rust/red/brownesh” color. The largest ones I have seen so far are maybe 1/10th of an inch. And the smaller ones are more white in color. I have meats, shrooms, and zoas I was about to transfer.

Any insight would be appreciated.

 

[EricR]

So many species of flatworms I'd hate to guess but I feel like the fact that they're on the glass is a good sign and likely just algae and pod eaters, but not sure.

Your description sounds similar to what I had for about a year and eventually they just went away (or population declined enough to where I never see any).

I had a post about a year ago here in case of interest but there are tons of flatworm posts on this site:
Flatworms

*picture/video in my post is under microscope so you see lots of color but, at normal size, I would've said more white and tiny, like you mentioned

 

[JGT]

The large one in the middle is a acoel flatworm. Not really harmful. Rest appear to be copepods and amphipods.