As I was cleaning the filter this morning, leaving the water still and without circulation, I looked at the water closely and began to see very tiny, white with a slight shade of brown worm like things floating and moving around in the water, I cant find anything like them online, they aren't very straight, but instead, they wriggle a lot and most tend to stay around the surface of the water, but all seem to swim upwards, for air I presume?, they all vary in size as well. From what I can see, there are currently at least a dozen of them, and I have no idea where they could have come from. from months ago if not almost a year ago, I stopped feeding my turtle feeder fish and earth worms after discovering that they can carry parasites, in terms of my turtle, I have yet to see any out of the ordinary signs or behaviors, his skin appears to be fine, his eyes are normal, he still has his appetite, and he isn't lethargic, in fact he's still energetic and curious as he usually is. He isn't showing signs of any respiratory complications either, but just as a precaution upon seeing the worms in the water, I immediately took him out until I could better understand the situation. If it helps at all, small, brown aquatic snails started appearing in the tank a few months ago with no apparent reason why or how, but I didn't think much of it at the time as I've heard they are beneficial, and provide an extra food source, even though he doesn't eat them often.
Could anyone give any information on what these small worms could be, where they could have came from, if they could be harmful or not, and if so, how do I get rid of them? I can provide images of them if needed.
Update: I'm now seeing some that are straight and not wriggling around like the other ones, and I do see some on rocks, and it appears that some are a reddish brown rather than completely white when I look very closely at them, or when they are not so much in the water, I also see some clustering together on the surface, I think they may be detritus worms which are actually beneficial, but I'm not completely sure, I also see them grouping (but not clustering) on the cuttlefish bone I put in the tank.
Update: After further research and behavior comparisons I'm now almost certain that these are detritus worms, I'll put my turtle back in the aquarium and closely monitor him and the worms for anything, as well as turn back on the filter as I don't see the worms going after the snails or snail larvae. But I'll keep this post up just incase anyone else has any speculations or suggestions on what it could be instead. Apologies if this is a lot to read.