I thought I had my guppy tank under control. Water quality is excellent. 25% weekly water changes. Still getting about 2 months out of a fish before it drops dead. Had a bad case of body rot (two months ago), thought that was licked. Recently fish would be fine one day, than hang out at the bottom the tank the next morning and by afternoon be dead. Typically losing a fish a week. Their gills movement would become very rapid right before death. Now one of my fish has the body rot again. Body rot is about in middle their body the skin will discolor, raised scales, tail movement will become very limited and then death. I try to keep around 10 adult guppies and 20 fry in my 75 gallon tank. Thinking guppies are just not going to work for me...never lost a gold fish in the tank in over 2 years. Thinking about going a different direction with tank. Can any one recommend more hearty fish? Any other live bears more decease resistant. How do rosy barbs fair? Thinking about taking my fish out of tank, wiping it down with bleach, boiling my substrate and filter in water to see if that will help?