hair-like worms in oscar tank?

Hi all.

I just did a 20% water change in my oscar tank this morning, like I do every other day because his tank is too small (55). He is recovering from hith, my fault.
I added aquarium salt, which I do once a week. (He didn't really seem to start healing until I started adding the salt.. now he's looking much better)
I added just alittle bit more than usual this time. Anyways I just went up to give him an earthworm (from my backyard) and noticed what seemed to be tiny hairs all over the place in the tank. They were about half the size of a regular cat hair. Then I noticed a few were wiggling. What is this?? Could it be from the earthworms? From the hith? Both fish seem fine (1 pleco in there with him)

Thanks

Sarah

Ok I think I found out what happened.. apparently these worms come from overfeeding your fish.. I vacuum the tank bottom everyday though and there is no substrate atm. This is the first time I've noticed them. I'll feed him less.. poor guy. If anyone has any advice or thinks this could be something else I'd appreciate it!!

Thanks!

Sarah