schisto is a flatworm. So prazi will do. But i have also read somewhere alinia can work if prazi fails. But prazi should do it.
If you also have roundworms, then it is not easy. I have them too. Bloodworms are treated with DEC or with prazi if they are flatworms.
The curved 2 worms together look very much like a schisto. You can have them from fish. The female lives in the body of the male and the male has a sucker to hang on the blood vessel. They can be found in urinary tracts as well.
Follow Matt's guidance on low dose prazi, once your PH is high enough.