If you do not have all that many or are persistent , you can easily suck them up with a turkey baster or a hypodermic syringe with piece of airline tube attached to it. Squirt the water and worms back out through a brine shrimp net, hung over the tanks side. I had a problem with some flatworms that came in on a rockfull of shrooms, and over a period of 3 or 4 days I probably sucked up a couple of hundred of those critters. You can get flatworm exit which is a chemical that kills em but I prefer the turkey baster or syringe method as it passes the time while playing with the tanks.
