Not sure if these are good or bad?

[cabinetmkr39]

I've been seeing these small worm like things in this tank from time to time . I think I remember these from
science class.

 

[mchambers]

Planaria. Not particularly harmful, but may eat tiny fry. Few, if any, fish will eat them.

Usual advice is to increase water changes and decrease feeding.

They also can be killed with dog dewormer powder, Fenbendazole, sometimes sold as "no planaria". Be careful with dosing if you try this.

 

[cabinetmkr39]

Thanks Matt Ill do the water change and feeding idea first .
Where did I get them?

 

[mchambers]

From what I've read, they can be introduced on fish or plants. My guess is that most tanks have them, but in small amounts.