I have used jungle parasite clear and a similar hikari one (at first) to treat the water, which has always worked. This worked on my red O, and he grew as normal, when my smaller tiger O hadn't grown much, i thought he may still have parasites, so i retreated with the same method, and used metro-something which i soaked his foods in (being an oscar it was easy enough to get him to eat it). This didn't have any affect really, becuase i dont believe he still had parasites. Anyways, he is now back in the big tank healthy as ever, has no signs of parasites, and i am confident he is parasite free. He never has stringy white poo, he isnt lethargic or anything like that. I think he is simply a slow grower.
