White/clear Worms

#1
Today I just noticed that I have these little white/clear worms crawling over the inside sides of my fishtank. They are only on one side too, which I found slightly odd. They crawl or squirm rather fast. Anyways... I was wondering what they are and if they are harmful to my fish. If they are then how do I remove the promptly?
 

Leopardess

Superstar Fish
#4
They are not harmful in and of themselves. They are "harmful" only because they indicate poor water quality and/or too much waste in the system. So yes you should remove them - but only to keep the tank cleaner. Generally, wastes in the substrate are a major culprit here. Gravel vac more frequently for awhile and maybe cut back on food a little.

A few of these are fine - a natural part of the tank system and add to biodiversity, all the while providing fish with a delicious morsel. Too many simply indicates that they have found a big food source (waste) and are thriving.

Do a search here for "planaria" and you will find more posts.