Metro and Prazi for suspected parasites in a pond

[Laura]

I have only rosy reds in a 6-700 gallon pond. When I bought them last summer, a few had white pin head sized lumps under their skin. It's spread now, and while they appear otherwise healthy, I would like to treat the pond. I assime that its a worm in the muscle tissue.

From my research it seems that metro and prazi may be effective. Does anyone have any experience with this, and any good suggestions of where to get reasonably priced meds?