guppy internal parasite

I have a six year old guppy colony that is not doing well. I have three females left, three or four fry, one or two juveniles, and unlimited males. The females all die young. Their spines curve and they die. They are still breeding. I isolated two of the three females incase make harassment is...

Hi   My Guppies seem to have internal parasites as their faeces are white. Its not stringy, just white in color. They are definitly less active. I tried one medication that was to be mixed with food (tummy wash from lfs). Now that isnt making much different. Some of them are spitting food out...