just an update, I have found medicated food for my fish. My molly is doing well, but my gourami is in bad shape. I don't think she will make it much longer. She was suffering from the stress caused by the nematodes. She has secondary infections but I am not sure if they are bacterial or fungal. Also, she is barely eating and I don't think she will be able to ingest enough of the medication to be worth while. Being a gourami, her intestinal cavity is very small and this causes about 25% of the worms to be hanging outside of her. I am tempted to manually remove them but it is said that this can do more harm due to secondary bacterial infection in the damaged intestinal wall. The worms are anchored with hooks. When the worms die, they will jsut fall out. I found a feed store (hard to do in a big city) that might carry Levamisole Hydrochloride. If not, I found an online livestock vet that sells it for $13. That is a ton better than the $200 that the pharmacy wanted. And get this, both the vet and pharmacy get the same product from the same company that makes it on the same machines.