Jay,
You mentioned, "...followed by a water change and a second treatment/water change".
I'd like to understand how quickly Praziquantel decomposes. If you initially medicate at 0.20 ppm, what would be the concentration after 10 days? (This would help me understand the necessary water change to keep the concentration at 0.20 ppm).
Have you had experience in concurrently medicating with CHloroquine and Prazipro? If so, could you elaborate on both your espoused methodology and/or your first-hand experience on this type of practice? (For incoming fish, I will treat them with Chloroquine at a concentration of 0.15 PPM over 30 days. The problem is that Chloroquine is not effective against flukes, so I have to concurrently also treat with Prazipro.) My concern and basis for the question above is that Chloroquine is a heavy metal and Prazipro is an organic, and one is not supposed to combine the two. (That being said, it appears that Copper is combined with Prazipro without any toxic reaction).