Parasites

[Trudy the Super Oscar]

I just noticed small white worms crawling around on the glass in my tank. What are these and are they harmful to my fish. Thanks

 

[CFC]

They are most likly just planarian worms and are harmless, they are a product of over feeding and bad tank maintainence so you need to look out how much food your are giving and how often you do water changes and clean the gravel/sand.