.18 now. There’s no downside in these repeated large water changes correct. Keep doing them until my ammonia stabilizes.What is the ammonia reading now?
Color changes in fish sometimes indicate stress, but that could go either way (light to dark, dark to light) and the water change itself could be enough stress to cause a change. As you probably know, fish can change color night to day. I usually don't read too much into that unless there is another symptom at the same time.
I'm not sure about your dad's tank - hypo is not completely risk-free, but generally, when you lose fish during it that means it was either done incorrectly (started too late for example) or the fish have a disease like Amyloodinium (velvet) that does not respond to hypo.
Jay
Ya my dads getting older and I convinced him on this treatment. He doesn’t read about this stuff. I control the tank. So when fish start dying I get blamed. Fun!