- Joined
- Feb 20, 2020
- Messages
- 64
- Reaction score
- 17
I was looking in my sump and noticed a few of these guys around, my tank is mixed LPS/SPS, ive noticed no damage on any of my corals or any of them being bothered. Should i be concerned?
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.

Yea i dont see them anywhere in my DT its kinda strange i do have a foxface maybe hes cleaning them up?Looks like a ghost flatworm
Do you see them on the glass in the display? They can get out of hand in numbers. A wrasse will eat them and keep the numbers at bay. FYI when they die, they can release a toxin in the water so using a product like flatworm ex I urge caution to have a water change ready and fresh carbon to run after.
I personally bought a 6 line wrasse to take care of mine and after a couple months I don’t see them anymore.

It’s very possible he’s picking at them and they are contained in the sump. They are generally harmless but more of a nuisance than anything else.Yea i dont see them anywhere in my DT its kinda strange i do have a foxface maybe hes cleaning them up?![]()
Thanks! Maybe ill pick one up for my sump, i actually just noticed i do have some in the DT i dont see any on any of my coral mainly on the glass i noticed with a flash light, i do have two cleaner shrimp already in there, hoping they are eating some of them. Not sure how i got them i dip everything...Those look like acoel (ghost) flatworms. From what I have read they are relatively harmless, they eat pods and detritus. I have had them a few times. Their population seems to self regulate.
I saw a video from Tidal Gardens where they were talking with a marine biologist about flatworm control. The biologist talked about a controlled experiment where they were able to get peppermint shrimp to eat flatworms. I happened to have a ton of these in my tank at the time and it made me curious. So I added 3 peppermint shrimp. The next day I couldn't find one single FW. I left the shrimp in there for a month just to make sure they got them all. I haven't seen one since.
Here is a picture of the acoel before I put the shrimp in the tank.
![]()
They probably came in on your macroalgae and have plenty of food from the pods and detritus in your fuge. They reproduce through fission so they can multiply quite rapidly when the conditions are right. I think they just go un-noticed until they are at critical mass because they are barely bigger than pods, they stay on the glass and substrate, and they don't seem to bother corals. They have probably been there for a while.Thanks! Maybe ill pick one up for my sump, i actually just noticed i do have some in the DT i dont see any on any of my coral mainly on the glass i noticed with a flash light, i do have two cleaner shrimp already in there, hoping they are eating some of them. Not sure how i got them i dip everything...