My betta has been displaying signs of Hexamita for several days (I didn't know what it was until I did a whole bunch of research and reading today). Because I have had a couple of unexplainable fish deaths (two neons) in the past week or so, I suspect the whole tank has some parasites, so even though it's 55g, I think I'll do a 90% water change and treat the whole tank. In addition to what is almost definitely Hexamita in the betta, many of my tetras show a tiny amount of mouth fungus. I've done some reading, and I think my best bet for the Hexamita is Metronidazole and/or Nitrofurazone. Can anyone weigh in on these medications and confirm that they will work? My betta has stopped eating, so food-based anti-protozoans are out at this point. Will either of these chemicals also treat the mouth fungus in my smaller fish? All knowledge and input is welcome; I'm not real experienced with fish diseases more exotic than Ich, and it's been several years since I even had to battle that.