Not looking to turn a trend or be some one who pretends to have all the answers.I think it's totally fine for you to hate it and never use it again. But it's also totally fine for the rest of us having success with it and keep using it. We all believe in our previous experience, they're all true even though they different.
A conversation like this won't push our husbandry much. What will really help is to find out what exactly cause the death. Is it oxygen depletion? Bacteria bloom? Did it trigger some sort of bacteria infection? Is it some actually toxicity in the medication? Is the tank got a tight cover without lots of surface agitation, and have been running in relatively low oxygen level and prazipro just pushed it over the edge? Why it works for many but don't work for you is the most important question. I always run a hob filter and have water level a bit lower, and run an air pump when running prazipro, yet still worry about oxygen depletion. Luckily it never happened.
Also API general care is a safer alternative. It has the same active ingredient for deworming. But it didn't have the secondary ingredient of prazipro, which trigger bacteria bloom.
this has happened to me recently more and more often, and when I reached out to some quarantine folks, they stated the same thing.
I was qting a gem tang, powder blue, and various wrasses a few months ago. A week of no meds, all was fine. Prazi pro and within a day , one by one fish went down.
to answer some of your points, not sure if it triggered a bacterial infection. Dosed at 10 pm, handful of the fish were dead at 5 am, 7 hours later, showing I mine to troubling signs with Jim an hour or dose.
All 20 gallon tanks I have connected do not have kids, not even screen tops. Running about 500 gph, which crashes down 4 inches from drain into sump. In there is a reef octopus skimmer rated for 250 gallons, with lid off running. In each tank is an airline tied to a piece of PVC, with bubbles breaking the surface. Each tank has a return line, aimed down at the surface creating a ripple.
agajn, if it were just me, I’d say I need to look harder. But when two vendors on here tell me they won’t use the stuff anymore, and another two quarantine vendors tell me they use panache, general cure instead for same reason, I think it’s fair to have that info out as well, this way people like me don’t see others in the past double dosing it because it’s so gentle and easy to use. I had a feeling the second I dosed it last night, things would only get ugly by the morning, and when I woke up and looked, I hated being right.
No bloom , yet, but will put uV light back on to prevent that.