Ohh ok. You're lucky to have a good LFS
available in your area.
I used Prazipro + aquarium garlic to get him to start eating. I used raw shrimp for best result. First thaw (from frozen) shrimp, then pour in some prazipro and garlic. Let it soak for 5min, then be sure your puff eat and swallow the shrimp. You will be lucky if he eats and swallow one bite. Sometimes they spit it out.
I wasn't aggressive on treatment for my first two 1-week treatment (each on different months). My puff spit it out a lot. The third time, I treated for 2 straight week and I made sure Barney ate the food and swallow. If hungry, my guy swallowed at least 1 bite and spit the 2nd and 3rd bite out. No garlic though.
Soaking food is many times more effective than treating water. Treating water does very little to kill parasites.