Are these "bad" flatworms?

KSzegi · Nov 18, 2013

I just noticed a few of these very tiny flatworms on my glass and I'm sure that means there are plenty more that I'm not seeing. I can't seem to find a definitive ID on the type - I don't think they are the truly "bad" ones but don't know for sure so thought I'd get some opinions!

nova65ss · Nov 18, 2013

Looks like red planaria I wouldn't call them bad but they can become an eyesore to some. They won't hurt any corals or anything in the tank.

KSzegi · Nov 18, 2013

From what I could find, they dont appear to be red planaria.......they lack the 3 lobes on their tail?

FMF0331 · Nov 18, 2013

I WOULD DESTROY THEM , BUT THAT'S JUST ME .. :boxing:

KSzegi · Nov 18, 2013

FMF0331 said:
I WOULD DESTROY THEM , BUT THAT'S JUST ME .. :boxing:

LOL .... yeah, that was my first reaction too. But trying not to get too wound up about them, hoping they are relatively harmless and they don't get to a real nuisance population.... but still looking into eradication methods short of chemical!!

moreef · May 26, 2021

KSzegi said:
I just noticed a few of these very tiny flatworms on my glass and I'm sure that means there are plenty more that I'm not seeing. I can't seem to find a definitive ID on the type - I don't think they are the truly "bad" ones but don't know for sure so thought I'd get some opinions!

Sorry I know this is old but I have the same looking pests in my tank like the small one on right. Are they red planeria? Have been dosing purge for 3 weeks and no change to amount I have been siphoning every week.

Baldguy · May 26, 2021

I have these same flatworms. It's my understanding that red planaria have the three point tail as OP said. I've seen these referred to as brown planaria. I've tried everything to get rid of them. None of the fish that people have had success with have worked. Flatworm Exit at much stronger doses than recommended has little to no effect. I have primarily LPS and they seem to like it. My duncan always has many I can spot on the polyps. Euphyllia also. I don't think it does any harm and I've learned to live with it though I would love to get rid of it.

moreef · May 26, 2021

Baldguy said:
I have these same flatworms. It's my understanding that red planaria have the three point tail as OP said. I've seen these referred to as brown planaria. I've tried everything to get rid of them. None of the fish that people have had success with have worked. Flatworm Exit at much stronger doses than recommended has little to no effect. I have primarily LPS and they seem to like it. My duncan always has many I can spot on the polyps. Euphyllia also. I don't think it does any harm and I've learned to live with it though I would love to get rid of it.

Seems like elevated nutrients can be a cause but mine are not elevated. I have a sixline but dont think he has any interest. Kind of surprised Purge is not doing anything yet that I tell. Will keep siphoning as I dont want them to become so bad that they cover my sps.