Brad, you probably weren't dosing enough Prime. To give you an idea, I was dosing almost 1 mL per day AmQuel into about 6 gallons holding an adult pair of Darwin clowns. I split the dose into two times per day. Remember AmQuel is twice the concentration of Prime. I like those SeaChem Ammonia Alerts too. They aren't overly accurate as I find the ammonia level is often 10x what the alert says. So if there is even a trace that shows up on the alert I do an extra dose.
I am surprised you killed fish with Formalin. I've never killed a fish with it, and I've used it for the better part of 20 years. Although one has to be very diligent about using a good fine-bubble airstone while dipping the fish. The carcinogenic effect that Formalin has does scare me though, so I only use Formalin as a last resort. I am also
very careful when working with it...I use gloves, eye goggles, the whole she-bang. The LC-50 of copper is way too close to the treatment level for me to be comfortable using it. Plus, hobbyist test kits suck in general and copper test kits are no exception so I'm not confident that we can test copper good enough to remain in that small window anyway.
Have you tried fishing for the Goby with a fish hook? Might need a permit.
