Can some one please tell me what these small 1 quarter inch thread like worms in my 125gallon preaditor tank are. They just showed up there, their very small and can barely be seen unless u look real close. I dont know where they came from,maybe the fishes excrement.My friend says hes had these in his tank for a long time but i dont appreciate them in mine. Can i rid these worms from my tank and if not will they hurt my fish? Someone please help.