IF they are the planiera , you can buy this dog dewormer and use less then 1/10th of a packet thier is 3 packets in the small dog form, it has to have the ingredent fenbendazole , I know this is what I bought and it worked for a 29 gallon, get the safe-guared small dog dewormer, and IF you use a very very small amount, it is safe for the fish & shrimp !! you can search the forums for this, that is where I found it . NOW if its the hydra , white, turns green (algea ) looks like a Y and it actually stings your pets , snails, shrimp etc. the only way I know of , is to take the paper towel method, and just keep using dry ones to wipe them out . I know thier is sonthing I used for these guys too, I will have to look it up again .... the worms are flat with eyes on the top of thier head (in a magnifying glass ) and I have even seen these bigger worms that most will say they are no problem, well to me they are HUGE problems . I belive thier are coming in with are shipments from a seller , I will not say who, but I think we have all bought from the same people, maybye not, but my main question here, is WHERE do they come from ?? I know the fish arent pooping these worms ? and they just pop up after a shimpment most if the time, esp when you do a nice cold water change , right > ? well they have to GO !! we need to find the problem get them to dose thier tanks with the wormer stuff, it is shrimp safe, gosh that right there is enough to use it !! and then just do water changes and keep fishing them out , I think the dead ones will float, or they just get eaten up with the filter , and mulm, so gravel cleanings, & water changes are a must till they are GONE !!!! HTH ~ and IMHO ~