Very small on the glass

[coastkid]

Can anyone tell me what these are? Good, bad and how to get rid of them if bad?

 

[dbowman5]

ouch looks like flatworms
look through the first sticky thread

What is that!! A R2R guide to common new tank hitchhikers.​

 

[coastkid]

Ok so bad. Never have seen them before. What do they eat?

 

[dbowman5]

some are bad some are neutral

 

[stanleo]

My first thought are acoel flatworms. They are harmless unless their population explodes. The are photosynthetic and can't handle much flow at all. Chances are they will go away on their own but a wrasse keeps them in check.