I have found some worms in my tank which are about the size of blood worm but about two hairs thickness, but instead of red they are light pink. They are very wriggly aswell, and sometime lots of them in a ball together. There is also something swimming around which I can only dicribe as very small, light greenish-white and look like a flea type thing, well they are too small to see in any detail. Has anyone got any ideas what these two things could be, and if they are harmful to the fish and/or me?